Declare Lord Xander as an attacker, attacking any opponent with an even library size.
Lord Xander's second ability triggers, causing the opponent to mill their entire library.

Infinite mill for target opponent

Lord Xander, the Collector

Bruvac the Grandiloquent

Declare Lord Xander as an attacker, attacking the opponent enchanted by Fraying Sanity.
Lord Xander's second ability triggers, causing the opponent to mill cards equal to half their library size, rounded down.
At the beginning of your end step, Fraying Sanity triggers, causing the opponent enchanted by Fraying Sanity to mill cards equal to the number of cards put into their graveyard this turn.

Combos with "Lord Xander, the Collector"