Melodias, Abyssal Evangelist

Whenever Melodias, Abyssal Evangelist enters
the battlefield or is dealt damage, gaze into the
Abyss.
Other black creatures get +1/+1 and nonblack creatures get -1/-1 as long as you've seen the
depths of the Abyss.
"There's no need to fear. The Abyss welcomes all with
open arms."