Why Can't I delete Champions

This is the right one. Because Kabam now makes challenge content that sometimes gates to lower tier champs or champs that have specific sets of abilities, they did not want players to sell champs thinking they wouldn't need them, and then complain when content specifically requires them.

Stellar

Well, one of the goals of this game is to gather all the champions so why would you want to delete some of them ?

If you don't want one of them, just simply ignore it, don't level it up and leave it Rank 1 level 1.
And who knows, maybe one day you will be happy to have this one for a specific event in which he will be mvp

EtherionGod

One of the best things Kabam has done was removing the sell option. I wish they did that when I was new to the game. I regret selling some 4 star champs just to get a 5 star crystal

Kabam Porthos

Hey @HenryfisherJr, while it used to be possible to sell Champions, we removed that ability for the reasons outlined in THIS announcement.