I know there's not any Pokemon Crossovers with Orochimaru in it, so I thought I'd make one. I own neither Pokemon nor Naruto, and if I did I'd be filthy stinking rich and praising anyone who created fanfiction based off of them.
Orochimaru looked around at what was going on. He'd performed a new jutsu with random hand signs that had come into his head when escaping from Sasuke during the fight with Itachi, but this was madness. He had no clue where he was, or even what on earth was happening. What was the worst was that he was being shrunken, and he felt his every fiber scream in pain as he was de-aged (not that he was complaining about that part), but to his delight, he was ten again. Not the age he was looking for, but close enough to give him chakra control and any abilities that he'd gotten as an adult to still be ready and available to him.
He looked around him in confusion as he landed in a crater. He saw a small human/fairy like creature with a third eye on its stomach, but it was closed. It smiled as a second creature appeared, this one a somewhat large dragon. It wasn't long before more creatures began appearing, but to his initial annoyance, he couldn't move to shoo them away.
"Hello, little human," a large creature said as it appeared, and he blinked in astonishment at the creature that resembled a woman with green hair. "Your attack was a dimension transfer. Well done, even we Gardevoir have problems with that sometimes. What are you called?"
"O-ro-chi-ma-ru," he croaked, and tried to swallow.
"Well, Orochimaru, welcome to our world," the Gardevoir smiled gently. "I think you'll find that you'll find allies in the most unlikely of places here, and even more so when it is voiced abroad about where you came from. For now, we will try to keep the random encounters to a minimum since you don't have a companion for your travels."
Suddenly, out of nowhere, a small green Pokémon appeared, and Orochimaru blinked in surprise as it healed him and touched its hand to his head.
"Celebi," Gardevoir murmured, "She wants you to know that you are welcome here. Also, she is saying that you will first be transported to the Kanto region by means of a young boy who will approach here soon. Our forest is not exactly hidden, but it is well out of reach to most trainers. Only the truly strong ones with loving hearts and who are champions in multiple regions may enter our domain."
Celebi quickly went over and lectured all of the Pokémon, who all nodded and scattered.
"Celebi told them that they are to voice it abroad about who you are and why you need help," Gardevoir translated. "She knows that you are from a war-ravaged world who specializes in combat, and that you are supposed to be in your fifties. She came from the future where you explained all this to her just before she and I helped take you back to your home after you complete your journeys of the five Pokémon regions."
Celebi tapped his cheek, and he looked at Gardevoir for a translation.
"You'll start in Kanto, then go to Johto, Hoenn, Sinnoh, and finally the Unova region, in that order," she translated, "I shall meet you in the Hoenn region when the time comes. We will alert each other to what region you are in. Be warned, you will face many hardships and must leave all your comrades behind from one region to the next. Each Professor will have a Pokémon for you, but let the Pokémon choose you. They will know from Celebi which one you need the most."
"Water," he croaked, and a large dog-like creature padded up and put its paw on a puddle-almost-pond to clean it for him.
He drank greedily, but was civil enough to use his hands to get the water from there to his mouth. The legendary Pokémon looked up, and Gardevoir nodded before Celebi vanished as well as the large dog.
"Thank you," he said to Gardevoir. "Can you tell it that?"
"Yes, I will tell Suicune of your thanks," she smiled. "Remember, some Pokémon will challenge you to fight someone from another world, while others will wish to join you in your cause. Take caution with who you choose to recruit. Your Pokémon partner from the Professors will nod or communicate a new recruit to you, and will probably assume an angry stance to protect you from an offensive and prideful challenger."
"Which will choose me first?" he asked confused.
"I do not know," she said wisely. "Let them come to you. Do not judge based on what the professors will show you, however. You must make sure that any and all possibilities are explored. The one that you are looking for to become your partner will race to you and leap onto your shoulder to show you that they are who you are to take with you."
"I see. Thank you for your help. What do I call you?"
"My species is Gardevoir, but I will tell you what I am called when we meet in the Hoenn region. You have a long road ahead of you, Orochimaru. Good luck, and trust the boy who will arrive shortly," she smiled. "Farewell until the Hoenn region."
"Bye," he said before going back down into the crater and sitting down and covering himself with his hands, just now realizing that he was stark-naked. "I hope this guy has a pair of clothes I can use…"
…
About an hour later, a young teenage male appeared of about thirteen. He looked at the crater and ran to the edge to find Orochimaru asleep on his side (he'd gotten bored). The young male yelped in alarm, causing the Sannin to wake up, but not move a muscle as he heard the teen sliding down the crater to see if he was alright.
"Hey," the teen said shaking him. "Hey, are you alright?"
He blinked at the male before cringing and covering himself. The young male realized what was wrong, and flushed with embarrassment.
"S-sorry," he said sheepishly as he pulled out a pair of pants, a shirt, and a pair of underwear. "I'm sorry I don't have a pair of shoes for you to borrow…"
"It's fine," Orochimaru said calmly, knowing beggars (as much as he hated to be called one) could not be choosers. "Who are you?"
"Brandon Birch, son of Professor Birch of the Hoenn region," he said as the young Sannin dressed. "You?"
"Orochimaru," he said calmly, causing the boy to wonder what had happened. "I was attacked, but I have no idea by what…"
"Probably a wild Pokémon," Brandon nodded. "They can be really strong in this forest. How'd you get here?"
"No idea," Orochimaru lied before realizing his worst pet peeve, "Unless I somehow became ten after being in my fifties."
Brandon laughed at Orochimaru's truthful statement, thinking it was a smart-mouth remark. The ninja didn't dare correct him – he'd be drilled about his world and forbidden from having a Pokémon if he told the truth outright and made sure the boy knew it. He pulled out a pokéball and released it into the air.
Orochimaru was startled by a large human-bird combination that was red coming out in a flash of white light.
"Blaziken, can you get me and my friend out of this crater, please?" Brandon asked, and the large creature knelt down and picked each of them up, one in each arm.
Within minutes, he'd leapt out expertly, and then set the two on the ground. Orochimaru blinked as Brandon pulled out the pokéball from before.
"Thanks, Blaziken. Return," he said calmly, and the large creature was returned to the ball in a retreating red light that had enveloped it. "What? You've never seen a Pokémon or pokéball before?"
The teen gaped as Orochimaru shook his head in fake awe. He sighed and motioned for the young ninja to follow him. Orochimaru obeyed, knowing he was at least not going to be challenged by a Pokémon while this boy was around to keep him safe.
So, that's said and done. The stage is set, now just to fill things out. I'll pick my pokemon for him based on what they look like as humans or their type disadvantages. I'll try to describe them as best I can in their human forms, but I'll provide some pictures as well or some links to the photos if you review or PM me. Either that or I'll put them on my forum en masse.
I will take requests, so please review!