Enchantment
Kicker
and/or
(You may pay an additional G and/or W as you cast this spell.)
When Stronghold Arena enters the battlefield, you gain 3 life for each time it was kicked.
Whenever one or more creatures you control deal combat damage to a player, you may reveal the top card of your library and put it into your hand. If you do, you lose life equal to its mana value.