Niron, God of Cowards

(cowards can't attack or block)
Walls can't attack or be tapped by effects
opponents control. Walls get +0/+1.
At the beginning of each opponent's end step if
you did not take combat damage this turn then
you get an experience counter, if you have 20 or
more experience counters then transform Niron
Niron hides from other Gods behind the safest
structure he could find.