Sorry this took a while I'm juggling a lot of things like working on FNAF OCs, studying for my driver's theory test, working on a video and anxiously awaiting my university acceptance.
While doing special training in preparation for his next World Coronation Series battle, our hero finds himself within the woods of forest near Saffron City doing some special training. Ash hurls a few discs into the air straight at Pikachu "alright Pikachu use Electro Web multiple times" Pikachu proceeds to use Electro Web and ends up trapping all the discs against or under the electric webs, Pikachu feels pride for catching the discs in one shot and on his first try in which Ash also praises him "that was awesome buddy". As they were about to head back Ash takes a moment and realises that they're near a cliff but thing was this was no ordinary cliff it was the same place where he unfortunately said goodbye to an old friend of his.
Ash takes a moment and sits down on a rock in which Pikachu notices something was wrong with him, Ash starts to remember the day he and Butterfree parted ways in which Pikachu also starts to remember their old friend and becomes a little down as well. However, Ash then then tells him "hey don't be sad buddy one day I know we'll see him again I promise maybe not today or tomorrow but someday…" just then they hear some ruffling in the bushes and become alerted of it. They get ready in case whatever comes out isn't friendly but to their surprise a wounded Butterfree jumps out and collapses in front of them, they become very surprised by it and check on it too "Ash woah a Butterfree and it looks hurt". Ash picked it up before it passed out but the thing was Ash noticed it was wearing a yellow scarf and then Ash immediately realised "Butterfree is that you".
Later Ash had brought Butterfree to the saffron city gym where Nurse Joy had treated his wounds and he was good as new, Nurse Joy rolled Butterfree out on a tray and presented him back to Ash "your Pokémon has been fully healed" Nurse Joy said. Butterfree was so happy to see Ash and Pikachu again that it immediately jumped right into Ash's arms "it's good to see you two Butterfree".
After getting reacquainted with their old friend Ash noticed Butterfree was looking very sad and became concerned about plus he had also noticed that Butterfree's mate wasn't with him, "Butterfree what's wrong is your friend okay and what exactly happened to you" Ash asked in which Butterfree gestured towards the cliffs. Ash and Pikachu realised something wrong was happening up there so they alongside Butterfree went to check out what the problem was.
After a while the three of them made it back to the cliff area and tried to figure out what attacked Butterfree so Ash asked "okay Butterfree what exactly attacked you" Butterfree was about to try and explain the best he could what attacked him but just then they all heard this weird ringing sound "what in the world could that be…" Ash then noticed Pikachu tugging on Ash's pant leg in which he points to Butterfree who was flying into the forest however Ash noticed that Butterfree was just mindlessly flying into the forest as he kept hitting trees along his way "Butterfree hey wait up".
They continued to watch Butterfree fly into the forest however they see two Venomths and a Beedrill flying in the same direction "what's going on" Ash wonders, Ash quickly grabs Butterfree however the other bug types continue flying. Ash and Pikachu look through the bushes and are horrified with what they are seeing, they witness what seems to be a large satellite spinning around emitting that ringing sound then they see the bug types flying towards it "so that's what's drawing in all the bug types…" they then take notice off lots of different Kanto bug types all sitting in cages with no escape, out of nowhere a net shows up and traps the three Pokémon making them unable to move then an evil looking man shows up and gloats "Pokémon poaching sure is easy when the suckers come to you".
This enrages ash in which he commands Pikachu to strike down the satellite with Thunderbolt and as Pikachu does a huge explosion erupts causing the ringing sounds to stop and makes Butterfree snap out of his trans. Ash became happy his friend was out of his trans however the poacher took notice of them "well look at what we got here a pint-sized trainer and his pint sized Pokémon, and do you know how hard it was to steal that satellite you blew up" Ash angrily retorts "how dare you trap and torture these innocent Pokémon" but the poacher replies "it's called making a buck and this is called getting rid of your problems, Houndoom make an example of this runt". He throws out a poke ball and then an angry Houndoom comes out ready to battle but then Butterfree flies up ready to battle as well which surprises Ash "Butterfree are you sure" Butterfree nods confidently so Ash gets ready to battle "all right let's do this".
While Ash and Butterfree were keeping the poacher and his Houndoom busy Pikachu snuck around to the cages in which he managed to find Butterfree's mate who was happy to see him so Pikachu uses iron tail on her cage and frees her but asks her and the other bug types to keep quiet for now. However, he unlocks more cages allowing them all to be free and they then all get into position to attack.
In the battle Houndoom strikes first using Thunder Fang however Butterfree manages to dodge it and attack with Tackle causing Houndoom get knocked off balance however Houndoom gets up and releases a Flamethrower but thankfully Butterfree counters it with Whirlwind knocking it back onto Houndoom but it still stood strong. Angry Houndoom manages to land and attack using Bite which caused Butterfree to fall to the ground however it rose back up again to fight however Houndoom was running in fast with a Flame Charge but Butterfree released a Stun Spore attack and caused Houndoom to become paralysed and unable to move, and to ensure victory Butterfree released Sleep Powder which sent Houndoom into a deep slumber and put him out the battle.
The poacher gets furious and returns Houndoom to his poke ball while Ash proudly remarks "seems I've won" but the poacher violently replies "this ain't over till I say this is over…" the poacher became interrupted when he gets hit in the back of the head by a small rock and looks over to see Pikachu with Butterfree's mate and all the bug types freed from their cages. The poacher becomes very scared and then most of the bug types use strings hot and tie him up then a Scyther lifts him up and leaves him dangling in a tree. The poacher admits his defeat "dangnabbit now your gonna Officer Jenny on that there Rotom-Phone and have her arrest me huh" Ash didn't realise though that his phone could do that "wow I didn't know it could do that thanks for the tip" the Poacher annoyedly states "me and my big mouth".
Soon enough Officer Jenny had arrived and arrested the poacher and took him away, meanwhile all the other bug type Pokémon were all happily released back into the forest going back to their homes and living peacefully. Now came the part Ash had been dreading ever since Butterfree got healed at the Pokémon Centre, they all went up to the cliffs and watched over a lot of Butterfree migrating. Butterfree's mate was waiting for him while Butterfree had to say goodbye once again to Ash "I knew we would end up coming back to the same spot where we parted" Ash said sincerely but Butterfree acted sad re living this whole thing again however he tried to make him feel better "hey this isn't goodbye again it's just see you later, we'll never forget you". Pikachu says his farewells to Butterfree and assures him they'll meet again.
Butterfree nods him head assuringly and gives them both a farewell hug, finally he flies off with his mate as they join the rest of the other migrating Butterfree. As they fly away Ash and Pikachu wave goodbye wishing their friend good luck.
Second goodbyes are always hard but sometimes fate will work in mysterious ways, as the journey continues.