Older Delve spells, like Treasure Cruise and Dig Through Time, were wildly overcosted by normal standards to compensate for the tempo advantage Delve offers
The card filtration gives you plenty to do with your mana, and I enjoy the synergy with cards like Collective Brutality and Inti, Seneschal of the Sun
White's removal is excellent with everything from O-rings to sweet targeted removal for any permanent and auras like Sheltered by Ghosts never hurt either
They sold out pretty quickly, but were keeping an eyeout to see if more become available
Are you going to take all the Swamps by leaving the rotting corpse of a multidimensional eldritch machine god to spread out and consume everything it can
Many Delta cards look almost identical to their Gamma versions, just with tiny tweaks to rules text or mana costs, though some brand-new cards appeared here, too