You may exert Trueheart Twins as it attacks. (It won't untap during your next untap step.)
Whenever you exert a creature, creatures you control get +1/+0 until end of turn.
Shoulder to shoulder until blade must turn against blade.
Illus. Matt Stewart
4/4
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KHANS OF TARKIR 
COMMANDER 2014
FTV: ANNIHILATION 
SPEED vs CUNNING 
MAGIC 2015 
CONSPIRACY 
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