Thinking of a few displaced stories and I'm conflicted on which to choose.

So you my friends will choose who I should do first! Here's a list of characters!

Shadow the hedgehog
Erza Scarlet from Fairy Tail
Pirate hunter Zoro from One Piece
Lucario
Axel from disgaea
Megaman x

Thinking of a story with discord and a human being best friends. Have any suggestions for how it goes?

I've heard of stories with human and pony relations. I'm Looking for stories with human having relations with any other species. Any recommendations?