Can we use Vanguard cards?
The Broodmother would give Sliver theme decks a unremovable
source of Sliver Tokens and give a player 28 life to start the
game with.
Sliver Queen, Brood Mother, Character, Starting Hand Size: +0, Starting Life: +8, Vanguard , Illus. rk post
3: Put a Sliver token into play. Treat this token as a 1/1 colorless creature.
Though long held captive beneath Volrath’s stronghold, the sliver queen is actually freer than most of Rath’s denizens. Her maternal instincts always take precedence—even when they conflict with the evincar’s agenda—and through her numerous litters, she ranges across all of Rath.