so we all know theres "raid bosses" in league, champs that become 4v1 to 5v1 machines if they get even a little ahead.(or are allowed to stack)
ie.
why not make some cool "boss battle " themed skins for them, like how veigar has final boss and urgot has giant enemy crabgot.
other examples? specific idead?
I just had an awesome Idea
all having a DJ sona like effect, where if they go onto their ult, it changes the music to a boss battle theme.
But 
already has two legendary skins. One of which is a mecha raidboss fight.
Honestly I don't think any of these champions need skins. They should just get REALLY BIG when they activate their ultimates (except for Sion who I guess could get slightly bigger based on his Soul Furnace stacks, up to a cap)
Well, three of four have ults which transform them into their, should I say, "Boss battle" form, while Sion, kind always has it going for him.
You forgot this guy: 
If he gets fed it is the end of days.
