27 cards where the card is tagged “opponent-lifegain”

Ajani, Inspiring Leader (Core Set 2020 #282)
Ajani Unyielding (New Capenna Commander #324)
Alms Beast (Gatecrash #141)
Aria of Flame (Modern Horizons #118)
Armistice (Commander 2014 #65)
Avenger en-Dal (Nemesis #2)
Benevolent Offering (Crimson Vow Commander #78)
Condemn (Ravnica Remastered #14)
Crumble (Masters Edition IV #147)
Dungeon Master (2016 Heroes of the Realm #2)
Fiery Justice (Double Masters 2022 #212)
Grollub (Exodus #63)
Grove of the Burnwillows (Iconic Masters #238)
Illumination (Mirage #21)
Invigorate (Double Masters #172)
Last Breath (Double Masters 2022 #15)
Lay Down Arms (The Brothers' War #11)
Nature's Claim (Iconic Masters #177)
Oust (Ravnica: Clue Edition #67)
Phelddagrif (Masters Edition #150)
Questing Phelddagrif (Planeshift #119)
Roar of Jukai (Betrayers of Kamigawa #140)
Skyshroud Cutter (Nemesis #118)
Soldevi Steam Beast (Alliances #133a)
Solitude (Modern Horizons 2 #32)
Swords to Plowshares (Murders at Karlov Manor Commander #88)
Wall of Shards (Coldsnap #23)

This search is finished. Now the real work can begin.