Gareth, Warrior of the Flame

Gareth, Warrior of Flame shares every keyword
of the other creatures you control and creatures
in your graveyard.(Keywords include flying, fear,
first strike, double strike, deathtouch, haste,
landwalk, lifelink, protection, reach, trample,
shroud, hexproof, vigilance.)
Why is everything on fire when he's around?
-anonymous