This spell can't be countered.
Trample
Surface {3}{U}{U}. Wrecking Whale surfaces tapped.

Vigilance, haste
Whenever you cast a spell, if its mana value is greater than Xeia's power, put a number of +1/+1 counters on this creature equal to the difference and create a Treasure token.

Whenever this creature attacks, exile up to one target creature card with mana value equal to 1 plus this creature's mana value from your graveyard. This creature becomes a copy of that card, except it has this ability.

Whenever a counter is put on another creature you control, you may put a counter of the same kind on Zeno. Then if there are no other counters of that kind on Zeno, draw a card. Do this only once each turn.