Black Cowl gives damage bonus high to everything.... It has become the most OPed item in the game....
Black Cowl vs Mercurial
Both give MSI low, but Black Cowl gives damage high, Black Cowl Wins!
Black Cowl Vs Snarby/skoalver
Black Cowl gives more damage to more items. giving more versatility.
Black Cowl Vs Vog
You can get asi bonuses on weapons but you can't get blanket damage bonuses on weapons, also with asi trinkets i think black cowl wins again.
Item, yes
But most OP set is Chaos Set