This is an aggro-control deck designed to take advantage of cheap spells and cantrips triggering Monastery Mentor and setting up delve spells.
The deck is constructed so that it spends the first turn or two disrupting the opponent with Inquisition of Kozilek, Thoughtseize, Spell Snare, and Remand while preparing to lay down a threat on turn three or four. With a T1 Thoughtseize or IoK, you can put down a T2 Thought Scour into Tasigur, the Golden Fang if you need to be on a more aggressive plan. Lingering Souls is also a very important card to help stabilize and give us game against decks that run Liliana of the Veil.
Snapcaster Mage has some fantastic targets in this deck with 7 mainboard removal spells and various other disruption and counterspells. There are several one-ofs in this list that can be found relatively frequently due to the amount of self-mill and cantrips. Sorin, Lord of Innistrad won't win every match, but his emblem can make Lingering Souls tokens and Monk tokens into scary propositions for the opponent.
Finally, Monastery Mentor, the namesake. This card is a powerhouse, even if removed within a turn of him landing on the field. Often you will want to wait until you have an instant to play the turn that you play him in order to get at least one trigger, but with all of the one mana spells and even the Slaughter Pacts, triggering his isn't hard. Once a threat hits the board and sticks, disrupting the opponent until we kill them isn't too hard.
Other win conditions for the deck are Tasigur, the Golden Fang and Creeping Tar Pit. Creeping Tar Pit is a currently under-utilized card that can steal games if an opponent doesn't have or used up all of their removal. Tasigur can be played T2 and that can break the back of an opponent who expects a slower, more controlling game.
A note on the maybeboard, most of the cards there are just potential cards for the mainboard. Cavern of Souls as a 1-of because all of my creatures are humans, Zealous Persecution to trump other Lingering Souls, Esper Charm and/or Think Twice for some added EoT card draw, especially because Think Twice can trigger Mentor twice, Mishra's Bauble for free Mentor activations on T3... However a few cards there would be sideboard material, like Dispel. The second Curse of Death's Hold also may want to be in if my meta has a lot of Twin players. A lot of cards to consider for this deck...
If you have any comments of suggestions, PLEASE let me know! I really want to have this deck perform well, and as I learn how to play it I want to see cards that I may not have thought of! Thanks for checking this out!