Your opponent doesn't normally see your cards with WarpWarp: You can play this from the top of your deck.on top of your deck. However, once Tesya's ability is activated by playing a unit, she is revealed to your opponent. She stays revealed while she is the top card of your deck until drawn.
Tesya, Omen Shaper is the fourth promotional card of Omens of the Past, after Colony Matron. Its promo quest period lasted for a limited time after November 28, 2017.