21 cards where the card is in the arena deck/cube and the text includes “gain” and the text includes “life” and the colors ≥ W

Adanto Vanguard (Ixalan #1)
Ajani, the Greathearted (War of the Spark #184)
Alseid of Life's Bounty (Theros Beyond Death #1)
Approach of the Second Sun (Amonkhet Remastered #4)
Cloudblazer (Kaladesh Remastered #189)
Conclave Mentor (Core Set 2021 #216)
Cruel Celebrant (War of the Spark #188)
Dawn of Hope (Guilds of Ravnica #8)
Doom Foretold (Throne of Eldraine #187)
Elspeth, Sun's Nemesis (Theros Beyond Death #14)
Emeria's Call // Emeria, Shattered Skyclave (Zendikar Rising #12)
Emeria's Call // Emeria, Shattered Skyclave (Zendikar Rising #12)
Glory-Bound Initiate (Amonkhet Remastered #21)
Heliod's Intervention (Theros Beyond Death #19)
Heliod, Sun-Crowned (Theros Beyond Death #18)
Integrity // Intervention (Guilds of Ravnica #227)
Knight of Autumn (Guilds of Ravnica #183)
Resplendent Angel (Core Set 2019 #34)
Skyclave Cleric // Skyclave Basilica (Zendikar Rising #40)
Skyclave Cleric // Skyclave Basilica (Zendikar Rising #40)
Sphinx's Revelation (Amonkhet Remastered #262)
The Birth of Meletis (Theros Beyond Death #5)
Trostani Discordant (Guilds of Ravnica #208)

Their mind whirled with grand plans, never thinking of what might happen if they got to the end of the list.