Veil of Summer is banned in formats like Pioneer because its a card that invalidates many game plans and it contributed to greens dominance for a time
Its an aggressive card, but its reliance on noncreature spells leads me to think that only black/red is interested in it
Ledger Shredder, Esior, Wardwing Familiar, the new Senu, Keen-Eyed Protector
Between attacks, convoke creatures, and Warden of the Inner Sky, it should be easy to enable its survival trigger, allowing you to exile Arclight Phoenix or Cauldron Familiar from the opponent's graveyard
That said, between ramps ubiquity in Commander, the fact that ramping one land for 2 mana has been good enough for many cards to see consistent play in the format for years, and the risk that Deep Gnome Terramancer will be a dead card is minimal at best, and Id call it a safe bet youll come out ahead far more often than not when playing this card