Maybe there's a quest that requires the unique skills of both sets of characters. For example, a powerful artifact has been lost that can control the weather. The Ice Age animals are used to dealing with ice and cold, so they could help Inuyasha and his gang find the artifact in icy regions of the feudal Japan. At the same time, Inuyasha's swordsmanship and knowledge of the local terrain would be crucial in protecting the group from demons and other dangers along the way.
Well, one possibility could be that the characters from Ice Age end up in the feudal Japan setting of Inuyasha. Sid could befriend Shippo, the fox demon. They might get into all sorts of comical situations together, like trying to find food in a world full of yokai. Manny, the mammoth, could be mistaken for a strange demon by some of the more superstitious villagers. And Diego might team up with Inuyasha to fight a common enemy, perhaps a powerful ice - based demon that threatens both their worlds.
A plot could involve a powerful jutsu in the Naruto universe accidentally creating a rift that leads to the Ice Age world. The Naruto characters then have to team up with the likes of Manny and Sid. For example, Sakura could use her medical ninjutsu to heal any injured animals. And in return, the Ice Age animals could show the Naruto gang how to survive in the harsh, cold environment.
Well, it could be that Naruto somehow gets transported to the Ice Age 2 world. Maybe he uses his ninja skills to help the animals there. For example, he could use his shadow clone jutsu to gather food more quickly for the starving animals during the ice age.
The characters would interact in some really interesting ways. For instance, Scrat from Ice Age, with his single - minded pursuit of the acorn, might drive Inuyasha crazy. Inuyasha is used to more straightforward battles and goals, and Scrat's antics would seem really strange to him. On the other hand, Kagome might find the Ice Age animals cute and try to protect them. She has a kind heart, and the animals' innocence would appeal to her. Sango would probably be a bit more cautious around the new - comers, but she would also see the potential in using them as allies against demons.
Well, the plot could involve the ponies somehow getting transported to the Ice Age world. Maybe Twilight Sparkle could use her magic in a wrong way and open a portal. Then they'd meet the Ice Age characters like Manny, Sid and Diego. The ponies' colorful and positive nature could contrast with the harsh Ice Age environment. They could team up to solve a common problem, like finding a way back home for the ponies while also helping the Ice Age animals deal with a new threat.
Well, a cool plot might be that the Ice Age animals discover a strange, glowing object which turns out to be a device from Danny Phantom's world. This device starts causing strange things to happen in the Ice Age, like creating areas of anti - gravity or making the ice melt in odd patterns. Danny Phantom shows up to retrieve the device and ends up teaching the Ice Age animals about his world of ghosts and technology while they all work together to fix the problems the device has caused.
One possible plot could be that Inuyasha somehow gets transported to the Twilight world. He might initially be confused by the modern settings and the presence of vampires and werewolves. Bella could mistake him for a new type of supernatural being. And Inuyasha, with his sword and combat skills, could get involved in the ongoing feud between the Cullens and the werewolves in Forks.
One possible plot could be that the Shikon Jewel gets scattered across the Marvel universe. Inuyasha and his friends, like Kagome, have to team up with the Avengers to retrieve the pieces. Iron Man might be intrigued by Inuyasha's sword and try to study it, while Captain America could admire Inuyasha's fighting spirit. They'd face villains who also want the power of the Shikon Jewel, creating an epic adventure.
It could be really cool. Maybe Naruto and his friends could end up in the Ice Age world. They might use their ninja skills to help the Ice Age characters. For example, Naruto could use his shadow clone jutsu to gather food for the prehistoric animals more quickly.
One possible plot could be that a character from Naruto with the Rinnegan somehow gets transported to the Inuyasha universe. Maybe they team up with Inuyasha and his friends to fight a common enemy. For example, the power of the Rinnegan could be used to counter some of the powerful demons in the Inuyasha world. The character might also introduce new jutsu or abilities to the Inuyasha gang, which could change the way they fight battles.
One possible plot could be that Thor somehow gets transported to the Inuyasha universe. Thor's powerful hammer and lightning powers would be a huge asset or a source of conflict. Maybe the demons in the Inuyasha world see Thor as a threat or a powerful ally to be manipulated. Inuyasha and his group might initially be wary of Thor but then realize they can work together to defeat a common enemy, like a powerful demon that is causing chaos across the land.