DRAGON BALL Z SKIN

Can't because of copyright, but they can make skins from mortal kombat, Sesame Street, etc!

As if the skins from Pacific Rim isn't ruining enough

Isn't copyright supposed to only mean you can't completely rip characters along with their names?

Besides Ezreal already talks about the scouter and 9000. Vi has Franky One Piece skin.

If we get a "Galactic Ezreal" skin with him wearing some sort of armor and blue clothing with a scanner on his eye, it doesn't break copyrights unless its outright the exact same outfit, exact move name on R like Final flash. But he will only resemble Vegeta but not be the exact Vegeta which is not copyright rule breaking if I am correct.

Take a look at Street Fighter's character Dan that totally copies Ryo from Art of Fighting in a parody fashion. He even uses a line Ryo uses (Ura ura) and exactly similar looking moves and its still not copyright breaking.

There are no copyright problems. Just because Riven gets a bike skin with Black clothes, blonde hair and a stylish sword doesn't mean she is violating Cloud Strife copyrights.

Of your list only Ezreal could be a viable Krillian. Lee is a better choice for Piccolo