Giygas

Deathtouch, Madness {b}{b}{b}{b}
Giygas costs {1} less to cast for every Black creature on the field, and takes double damage from White sources. If killed by a White source, Giygas may not activate Madness.
{b}{b}{b}: Destroy target creature. Indestructible and similar cannot prevent this.
"You cannot grasp the true form of Giygas' attack!"