Explosives Stockpiler

When Explosives Stockpiler or a creature that
shares a color with it enters the battlefield under
your control, put a charge counter on Explosives Stockpiler.
Tint {2}{w} (This permanent becomes white)
Whenever a creature attacks you, if Explosives Stockpiler is white, you may sacrifice it. When
you do it deals damage equal to the number of
counters on it to target attacking creature.