Flash (You may cast this spell any time you could cast an instant.)
At the beginning of each player's draw step, that player draws an additional card.

As Hall of Triumph enters, choose a color.
Creatures you control of the chosen color get +1/+1.

Flying, lifelink
Heroic — Whenever you cast a spell that targets this creature, put a +1/+1 counter on this creature.

Constellation — Whenever this creature or another enchantment you control enters, draw a card.

Constellation — Whenever this creature or another enchantment you control enters, creatures your opponents control get -1/-1 until end of turn.

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

This creature enters with four +1/+1 counters on it.
: Put X +1/+1 counters on this creature, where X is its power.

When this creature enters, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

Flying
When this creature enters, it deals damage to any target equal to the number of Mountains you control.