The problem is that it becomes a mana sink that you can only use on your own turn, rather than a way to invest leftover mana at the end of an opponent's or immediately after they drop a board wipe
Casey decks often lean into fast, Turbo-style strategies built around casting him early, finding fast mana and combo pieces, and using as many cards as possible before the upkeep trigger arrives
Its also an enchantment creature, like FOMO, so it counts twice for Delirium
Tapping and activating only as a sorcery will keep Sequence Engine from getting into Scavenging Ooze territory
There will be starter decks released with each set alongside randomized booster packs
Vito, Fanatic of Aclazotz Vito, Fanatic of Aclazotz requires you to sacrifice multiple permanents in a turn for its full value