Declare Fleet Swallower as an attacker, attacking any opponent with an even library size.
Fleet Swallower triggers, causing the opponent to mill their entire library.

Infinite mill for target opponent

Fleet Swallower

Bruvac the Grandiloquent

Declare Fleet Swallower as an attacker.
Fleet Swallower triggers, causing the opponent enchanted by Fraying Sanity to mill cards equal to half their library size, rounded up.
At the beginning of your end step, Fraying Sanity triggers, causing the opponent to mill cards equal to the number of cards put into their graveyard this turn.

Combos with "Fleet Swallower"