Thrymn, Stormking

Prevent all damage that would be dealt to
Thrymn, Stormking by creatures with mana
value 2 or less.
Whenever one or more giants you control deal
excess combat damage to creatures in combat,
you may cast an instant or sorcery spell from
your hand with mana value X or less without
paying its mana cost, where X is the total excess
combat damage dealt.