Shui, the Water Hole

{t}: Add {u}. Put a +1/+1 counter on Shui instead
if it entered the battlefield this turn.
Convene {10} — Shui becomes a 0/0 Elemental creature until end of turn. When it deals damage
to an opponent this turn, put a +1/+1 counter
on it. Then you may move any number of
counters from it onto target creature you control.
(Your creatures can help activate this ability. Each creature you tap while activating this ability pays for {1} or one mana of that creature's color.)