Rhysta can't block.
Summon: Draw a Shadow Sigil from your deck.
Empower: +2 Strength and Warcry this turn.
Card sounds may differ from in-game as they get updated.
Empower - Does something when you play a power card.
Summon - Does something when played
Warcry - Each time a unit or Relic Weapon with Warcry attacks, it grants a permanent bonus to the top-most unit or weapon in your deck. Even if it's a few cards down, you'll get to stack up the bonuses on it over multiple turns.