Emerald Ronin

Glow (Whenever you cast a spell, put a glow counter on this permanent. At the beginning of your upkeep, remove a glow counter from this permanent.)
Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
If a source would deal damage to Emerald Ronin, prevent X of that damage, where X is the
number of glow counters on Emerald Ronin.