Registeel

Golems you control get +1/+1 and have vigilance.
When Registeel attacks or blocks, artifacts and
Golems you control get indestructible until end
of turn.
Whenever a Golem you control with indestructible attacks or blocks, it gets +X/+X
until end of turn where X is the number of permanents you control that gained
indestructible this turn.