mtg oath cards Chandra, Flamecaller [Oath of the Gatewatch] You may activate the loyalty abilities of planeswalkers you control twice each turn rather than only once. Magic The Gathering Trading Card

It works specifically well in decks with Polymorph, which can get it into play early on

THIS BUNDLE INCLUDES: Includes 24 booster packs, each with 12 cards

Then there's Anthem of Champions, an extremely basic, but very cheap Anthem effect that makes all creatures stronger

Instant Kindred - Faerie Color tag templates(None) Pongify Destroy target creature

But getting a spell from the top 4 cards of your library sounds even better

Ursula allows you to discard a non-character card of your choice from your opponent's hand every time she quests, which is an incredibly powerful effect that, unlike similar abilities, can be repeated multiple turns