Aside from being a human, which is a very relevant creature type in Commander, Modern and basically every other MTG format, Esper Sentinel is good because it reads: Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays X, where X is Esper Sentinels power. Its a bit like Rhystic Study, but the cost can be far higher if youve got things that make humans stronger or you can put +1/+1 counters onto Esper Sentinel
Outside-the-box cards: Reap, Gravestorm Phenax, God of Deception Phenax kind of builds itself, but instead of a raw mill deck, Id rather go with something that mills things so that you can use them
Maximus Palace Horse Character Type: Ally Affiliation: Storyborn Bodyguard: This character may enter play exerted
Then, choose a number of your opponents Pokemon equal to the number of Energy you discarded (you may choose the same Pokemon multiple times)