spellbook deck yugioh of Judgment [RA01-EN054] Quarter Century Secret Rare Type monster whose Level is less than or equal to the number of cards added to your hand by this effect My Spellbook Prophecy Yugioh Deck

Paying two extra mana to get the "gotcha" Thragtusk from your sideboard just isn't usually worth it in a format like Legacy

Not only can it be used for Xyz summons, but it can also be used to its effect

You can then cast the creature half of it directly from exile by paying its normal mana cost

Aside from Standard, Pioneer, and Limited, here's what's exclusive to Arena: Alchemy: This is essentially standard

" monster you control destroys an opponent's monster by battle and sends it to the Graveyard : Target 1 "T.G." Synchro Monster in your Graveyard

How effective Smothering Tithe ends up being, however, depends on the table