Shriekmaw [Commander 2014] The New Challengers You can only use this

You can only use this effect of "Soul Servant" once per turn

you can negate its activation and destroy it

elf insurgent

Set: Duelist Pack 4: Zane Truesdale Card type: Quick Play Spell Rarity: Common Attack: 0 Defense: 0 Return 1 Fusion Monster on the field to the Fusion Deck

Exile Spelltwine

Shriekmaw [Commander 2014] The New Challengers You can only use thisSet: Commander 2014 Type: Creature Elemental Rarity: Uncommon Cost: {4}{B} Fear (This creature can't be blocked except by artifact creatures and or black creatures.) When Shriekmaw enters the battlefield, destroy target nonartifact, nonblack creature. Evoke {1}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)