27 Apr 2018
If an effect says that a creature loses hexproof or can be targeted as though it didn't have hexproof, this applies to hexproof from black as well.
27 Apr 2018
"Hexproof from [quality]" is a variant of the hexproof ability. "Hexproof from black" means "This permanent can't be the target of black spells your opponents control or abilities of black sources your opponents control."
27 Apr 2018
Knight of Grace only gets +1/+0 if any player controls a black permanent, no matter how many black permanents players control.