Omniscience

Omniscience is a Watcher rare skill that lets you choose any card in your draw pile and play it twice for 4 energy, then Exhausts. Choosing any card in your deck and playing it twice for one 4-energy cost is incredibly powerful: playing a 30-damage Wrath attack twice means 60 damage total. Playing a power twice doubles its activation. Playing Crescendo twice would enter Wrath twice (which in practice just means you're in Wrath). In Divinity, doubling a 30-damage attack means 60 base doubled to 180 total damage.

Omniscience is best used as a setup for an explosive turn. The 4-energy cost is steep, but the ability to target any card — not just one in hand — gives extreme flexibility to hit your best card precisely when needed. Targeting a high-damage attack in Wrath or Divinity creates burst damage above any other card. Multiple copies compound (using Omniscience to play another Omniscience for free). Upgraded, Omniscience no longer Exhausts, allowing it to fire every combat instead of only once, and be used multiple times if drawn again in long fights.