-Flashback five years ago-

A young Guilmon just sat in sadness, for a seal in the cave had been opened and the Black Digimon had been freed.

"Five years ago, I accidently freed the Black Digimon because of the seal. My curiosity got the better of me. I was still just a kid, but I knew I had to do something." Guilmon explained as his past self then looked up, still saddened, but he knew what he has to do.

"I decided to bring myself to stop the Black Digimon. It's my fault that they were freed and thus it was my responsibly to set things right. But I also thought I betrayed myself at being Takato's Digimon, so I went to find someone who could replace me for being his Tamer. That is when I met Agumon." Guilmon then said.

The next scene showed Guilmon and Agumon meeting together.

"Huh? You want me to replace you as Takato's partner?" Agumon asked in surprise.

"Yes, Guilmon does." Guilmon replied.

"But why? I don't understand." Agumon asked, confused, before saying. "You and he are so powerful together. There's no way I can take your place, Boss."

"Because Guilmon has done something very bad. Guilmon must do something about that and fix problem Guilmon caused." Guilmon replied and then said, reaching out to Agumon. "Agumon take Guilmon's place as Takatomon's partner. Please, for Guilmon?"

"But Boss..." Agumon began to say, only for Guilmon to place his right hand to his belly.

"Guilmon give Agumon some of Guilmon's power." Guilmon said as a red aura appeared around his hand, which he then brought to Agumon's stomach, causing a Hazard symbol to appear on the amber coloured Digimon's stomach. "Guilmon must go, Agumon take care of others."

And before Agumon could say another word, Guilmon then left, making Agumon look at the new marking on his stomach and nod, seeing it as a new responsibility and a show of respect from the red dragon Digimon, to which Guilmon then said. "After I gave part of Takato's power to Agumon, I began to search for BlackGuilmon and the others. I then followed them to the DigiVixen Kingdom."

Guilmon hid behind a section of fallen debris, watching as the BlackGuilmon had just defeated and deleted Sakuyamon, had Queen Taomon captured and were reaching for the Digi Crystal.

"They were trying to steal the Digi Crystal. I overheard their plans." Guilmon then narrated.

"Tell me. What do you plan to do with the Digi Crystal?" Taomon ordered as she was being restrained by BlackAgumon and BlackLeomon.

"We have built a machine to allow us to drain the power of the Digi Crystal to weakened the Digital World and also all the Digimon and then fire it's deadly laser to destroy the Real World. Once the Digital World is weakened, we shall enslave all the Digimon with our dark power and make them work for us in making the Digital World our own world, a world full of despair and darkness." BlackGuilmon said in a wicked reply, shocking Taomon at their evil plans for domination and destruction.

Guilmon teared more at the thought of Takato and the others in peril.

"But enough was enough. I had to do something." Guilmon told his friends, before the bearer of the Digital Hazard mark then glared, still crying as he came out from his hiding place.

"BlackGuilmon!" He yelled, making all the Black Digimon then face him, causing BlackImpmon to mock. "Oh look who's here? The little red dino who freed us."

"Guilmon's fault that you are freed. Guilmon stop you!" Guilmon shouted in reply, making BlackAgumon smirk and say. "You stop us? You're too weak to defeat us. You're just a child."

But Taomon, gazing upon Guilmon, sensed something in Guilmon's soul and called out to him.

"Little one! If you want to stop them, take the Digi Crystal and go somewhere safe! I shall meet up with you later!" She called to him, making Guilmon look at the crystal and then to Taomon, in which the red dragon Digimon then nodded and rushed towards it.

"Stop!" BlackTerriermon called out as they all were about to attack him, only for Guilmon to dodge each one attack, before he met up with BlackGuilmon, pushed his Dark half out of the way and grabbed the Digi Crystal.

"Go! Run! I meet up with you soon!" Taomon called out, making Guilmon nod and ran away, holding the crystal close to his chest.

"Get him, you fools! Don't let him get away!" BlackGuilmon ordered in rage, making his Dark minions, as well as BlackAgumon and BlackLeomon, who let go of Taomon in anger of what Guilmon had done.

However, Guilmon ran so fast, determined not to let the Digi Crystal fall into the hands of evil, he soon lost them.

"I have secured the Digi Crystal and found a good hiding place in a secret cave. However, while I hid, I began to realise. No matter what I do, I will always be a small child. But then Taomon appeared." Guilmon explained, before his past self then saw Taomon, along with a different Leomon, wearing a brown scarf, appear in the cave.

"Little one. You stopped the evil one's plans for now, but they now targeted you and won't rest until they find you." Taomon warned, making Guilmon say back. "Guilmon must stop them! Guilmon has to get stronger, but Guilmon too young."

"Not necessary. You can grow more stronger if you train. Here, there is a secret room deep in this cave where you can spend days of training in a year. Also, we can help you grow more stronger and mature. Leomon here will train you himself. After you, you are the hero in the legend." Taomon replied, making Guilmon ask, his tone full of surprise. "Guilmon is hero?"

"That's right." Leomon replied, before saying. "You may not know but you are the Hero of Both Worlds. However, you're too young to be one. But we can help you grow in a more mature person. Look in the digi crystal and you can see your future."

Guilmon looked deep in the crystal, and saw a more adult, muscular and mature version of himself.

Knowing he had to become this Guilmon, Guilmon nodded, determined to achieve such power and defeat the Black Digimon.

"Very well. I shall train with you here." Leomon said to Guilmon, before he faced Taomon.

"Your majesty. Go and wait for his friends to come. They may be searching for him as we speak." Leomon said in a serious tone, making Taomon nod in understanding.

Guilmon was shocked, causing him to say. "But Guilmon don't want to be found!"

"Relax. It'll take five years for them to find this place. But the legend states you must join your friends again. Though I have lost my daughter who was a princess a long time ago." Taomon said, saddened at the memory of losing her daughter.

Guilmon was shocked to hear what he had heard, in which he put two and two together and asked. "Daughter? Queen mean Renamon? Renamon princess?"

Hearing that, Taomon gasped, before she had to ask, hoping Guilmon may be the key to being reunited with her taken child. "You know her?"

"Yes. Renamon friend of Guilmon but..." Guilmon replied, looking down, still ashamed at the evil he had released and the dangers he had put his friends and both the Real World and Digital World in.

"Then that makes you more close to your title than you know. I am glad you know my daughter. Now, keep the crystal safe and start your training right away" Taomon said, smiling at Guilmon, before she took her leave.

"And thus, my training began. Leomon helped me improve my knowledge and speech first. I kept reading countless books and memorising every knowledge there is. I even learnt the secret of Digivolving. Then four years later, I had aged a bit but now it's time for me to do some proper training." Guilmon explained, showing his past self was seen reading books and writing on a blackboard, while Leomon watched.

And as time went on, Guilmon began to grow.

He was slightly taller before he and Leomon had met, before Leomon brought him into the special room for further training.

"I trained for the remaining year but in that room, felt like three years. Leomon helped me brush on my fighting skills, help me train hard as possible." Guilmon said, his past self was on the ground, lifting up huge weights with both hands, while lifting little ones tied to his legs, before his training changed to him dragging behind a huge rock which was tied up and wrapped around his chest.

Through his training, Guilmon was sweating a lot, but continued to make progress as his stomach slimmed down, impressing Leomon at how far and quickly Guilmon was growing.

As time went on Guilmon and Leomon sparred a lot, exchanging punches and kicks, though Leomon did get the upper hand most of time.

But as time passed, Guilmon grew as tall as Leomon and managed to lay some hits back.

With his skills improved, as well as seeing that his arms and legs were more muscular, Leomon smiled, proud of Guilmon and his development.

The next day, Leomon saw Guilmon had started to train solo, in which he saw Guilmon's hands covered in blood as he was punching huge rocks and not soon stopping.

But concerned for him, Leomon managed to convince Guilmon to stop so he could wrap Guilmon's hands in bandages in a cross-like style.

"Soon... I was finally more powerful enough to deal with those Black Digimon." Guilmon said as he and Leomon finally walked out of the room, with Guilmon's more mature and muscular body revealed, and the Digi Crystal still in his possession.

"But before we return to the Queen, Leomon and I took one small task. We had to put our skills to a final test. We ran into a Piedmon, who came to assassin the queen." Guilmon then said, remembering fighting Piedmon, who used his knife to slay Leomon, causing Guilmon to defeat Piedmon with a powerful clawed strike through the clown's chest.

"Leomon didn't survive." Guilmon told his friends in a saddened tone as his past self rushed to Leomon's side, making Leomon look up and smile weakly. "You've gotten more powerful... Now since you can handle someone like Piedmon by yourself, even as a Rookie... I'm so proud of you..."

"Master Leomon... we already lost Jeri's... you can't go too..." Guilmon said in sadness, pulling Leomon close and holding him.

"Don't let the despair of me get to you... You know what you have to do, Hero of both Worlds... Save the worlds... and defeat BlackGuilmon... that is your destiny..." Leomon said, his ending words before he burst into countless Data particles, leaving his brown scarf behind.

With Leomon gone, Guilmon looked saddened for a moment, but then he nodded in reply and picked up the scarf.

"I fight for all of us. Watch me, Master Leomon." Guilmon said as he put the scarf around his neck and then tied the ends together in a last show of respect to the one who had helped make him the Digimon he now was.

"With Leomon's words in my heart, I prepared to return to return to the Queen. However, the first one I saw on my return..." Guilmon explained, a past copy of his being was walking through the cherry blossom forest, where he then saw Renamon before him.

"... was you, Renamon."

-End flashback-

"And that was my story." Guilmon then said, ending his tale and leaving most of the Digimon Tamers surprised at what Guilmon had done and been through, before Henry spoke up and asked. "So that's why you disappeared for five years?"

"Training to defeat those Black Digimon. You must be determined." Terriermon commented in an impressed tone.

Takato smiled, not only from seeing how strong Guilmon had gotten, but to see his Digimon back, making the brunette say. "And with the gang back together now we can defeat the Black Digimon."

"And go, you must all go now." Taomon then said as she approached them.

"Renamon, dear. You must save the digital world with Guilmon. Take the crystal with you. Return it after the Black evil is defeated." She told her daughter, who nodded in reply, before giving it to Takato, who put the crystal in his backpack.

While the group were ready to head off, Renamon rushed over to Taomon for a final time, wrapped her arms around her mother and said as she hugged her closely. "Mother... I will come back. I promise."

"Shall we go, Boss?" Agumon asked, making Guilmon look at him and then nodded in reply.

However, Rika then spoke up as something Guilmon had said had gotten her curious, making the Digimon Queen ask. "The secret of Digivolving? You mean you can find a way to Digivolve without our powers?"

"I'll explain on the way" Guilmon replied as they all walked away.

Watching the hero, his friends and her daughter leave, Taomon smiled and whispered. "Hero of Both Worlds and my daughter. Their fates will be together more closer than before. Good luck to you all."

-Meanwhile, with the Black Digimon-

BlackGuilmon sat on his throne, speaking with BlackLeomon, BlackCalumon and BlackGuardomon on his communicators, which looked like dark copies of the Tamer's D-Powers. "The time has come. Find those annoying Tamer brats and bring the crystal and the princess to me."

He then smirked evilly as a new plan to obtain what he desired was soon to come into fruition, one that would push Guilmon to his limits.