One idea could be that Pennywise from 'it' somehow enters the world of 'Devil May Cry'. Dante could mistake Pennywise for a particularly grotesque demon and engage in a battle. Pennywise, with his shape - shifting abilities, would constantly change forms to try and deceive Dante. Another plot could involve the characters from 'Devil May Cry' being lured into Derry by Pennywise's illusions. They then have to fight their way out while also dealing with the psychological warfare that Pennywise is known for.
A possible plot is that Pennywise tries to possess one of the characters from 'Devil May Cry', like Dante. The other characters then have to figure out how to exorcise Pennywise without killing Dante. They could seek help from the more knowledgeable characters in their world, like Lady or Trish, who might have some knowledge about demonic possession and how to deal with an otherworldly entity like Pennywise.
One idea could be Dante from Devil May Cry being summoned to the world of Devilman by Akira. Akira could seek Dante's help to fight against a new type of devil that is beyond his capabilities. Dante, with his arsenal of weapons and devil - slaying skills, would then team up with Akira in his devilman form to take on this new threat.
A plot could revolve around a new enemy that threatens both the world of How to Train Your Dragon (where Toothless is from) and the Devil May Cry universe. The characters from both universes have to team up. For example, Vergil might be initially skeptical of Toothless but then come to respect his power. Toothless could also interact with the different weapons and magic in the DMC world in an interesting way.
A crossover with the Castlevania universe would also be cool. Dante could find himself in Dracula's castle, facing off against classic Castlevania monsters while also dealing with his own demonic foes. It would be interesting to see how he interacts with the Belmonts.
A possible plot is a magical artifact from Fairy Tail's world that is sought after by demons in Devil May Cry's universe. The Fairy Tail gang teams up with the Devil May Cry crew to protect it. The artifact might have the power to either destroy all magic or enhance it to uncontrollable levels. Dante and Natsu could have a friendly rivalry over who is stronger and who gets to fight the main villain. Another plot idea is that some of the Devil May Cry characters are sent back in time to the Fairy Tail world's past. They have to adapt to the magic - based society and help the Fairy Tail founders with a great threat that was once thought to be long forgotten.
One idea could be a story where Dante discovers a hidden demonic realm within the human world that has been influencing events without his knowledge. He has to team up with a new, inexperienced hunter to navigate this strange place.
One idea could be a crossover with the Bayonetta series. Dante and Bayonetta could team up to fight a common, powerful demon. Their different fighting styles would make for some epic battles and interesting interactions. For example, Dante's flashy swordplay combined with Bayonetta's acrobatic and magical combat.
One idea could be that Naruto somehow ends up in the Devil May Cry world. He might mistake some of the demons there as similar to the tailed beasts he knows. For example, he could try to 'befriend' a demon in the DMC world thinking it's like how he dealt with Kurama. Another idea is Dante teaching Naruto some swordsmanship. Dante's flashy and powerful combat style could blend well with Naruto's own energetic fighting moves.
One idea could be Dante from Devil May Cry being mistaken for a new, powerful superhero in the MCU. He then has to deal with the Avengers being both curious and slightly suspicious of him. Another plot could involve Vergil somehow getting caught up in a battle against a major MCU villain, like Thanos. Maybe he initially wants to use the chaos for his own gain but then realizes the greater threat and teams up with the heroes.
One idea could be that Dante from Devil May Cry gets transported to the wizarding world of Harry Potter. He could mistake the wizards' magic for some kind of demonic power at first. Maybe he'd try to slay a Hippogriff thinking it was a demon, creating chaos at Hogwarts.
One idea could be that the characters from RWBY end up in the Devil May Cry world and have to team up with Dante to fight off a new type of demon that is attracted to the unique Aura energy of the RWBY characters. Another could be a crossover where Nero and Ruby exchange their weapons for a short time and learn from each other's fighting styles. Maybe Yang could also have a friendly sparring match with Vergil to compare their strength and swordsmanship skills.