Let me just say: Leovold is one mean deck. Don’t play this deck unless your metagame is super competitive 0r you don’t want any friends in life.
Teferi’s Puzzle Box just locks people out of the game. The way I believe it works is they draw the card for the turn, and then but all their cards to the bottom of their library, and then draw no cards, since they’ve already drawn the one card that Leovold allows. Font of Mythos and Howling Mine make it so just you draw extra cards. There are several other cards like this like Kami of the Crescent Moon and Dictate of Kruphix, so this is just so you get a feel for the kind of the cards that go into decks like these.
Both of these are basically XU draw X cards, since no one else will help you draw more cards off of Minds Aglow.
These cards are brutal. It makes everyone discard their hand, and then draw only one card, since that’s all Leovold let’s them draw. There are many more card like these, these are just a few examples of these types of cards.
Geier Reach Sanitarium is also some nice utility land bonus to help you empty their hands.
Shrieking Affliction and Psychosis Crawler are both win conditions in this deck. Shrieking Affliction bolts opponents during their end steps, and Psychosis Crawler makes opponents lose a ton of life and it hits for a ton of damage since you’ll be drawing tons of cards.
What do you think?