For the same reason as Karthus. There is fuck-all that can be done against 5 simultaneous (or worse, spaced out) 1500 damage AP Malphie ults. It's horrendously unfun to play against, and boring to play as, because it is without question a guaranteed win. It absolutely ruins an otherwise fun game mode. Speaking of which, Malphite in general could use some toning down (like removing his ult entirely) but that's a discussion for G&B.
same with gp and his global ult
Banshees and zhonyas I guess. Although i have won against him as ziggs last year (or year before that). Just space out a little. I haven't vsed any malphites yet tho cause hes bloody boring to play.
You mean like 
, except they're all basic abilities? Granted we beat them, but that's only because we had 5 
, and we all know they can proc each other's Silver Bolts and absolutely destroy everything that exists in this game.
Or how about 
. One of them lands a knock-up, the other 4 do too and you just die to cheesy burst you can't avoid once you get hit once.
is another fun one that you can't really do much about.
Or 
.
Let's be real, the majority of these OFA's are cancerous to play if you just happen to have a slightly bad match-up, because that alone turns into a "Hah, everyone got counterpicked." situation.
I rather see Kass be removed from One For All.
