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
This guide breaks down the visual and textual clues that signal true rarity and potential investment value
Twilight Masquerade is a fantastic set to explore because it contains many cards that could potentially see competitive play
Single-handedly pushing out 1-toughness creatures from Modern while it was legal (well, maybe Wrenn and Six has some say on that too), format-warping is a phrase that some would happily use for this card
Would you make any changes if you had the power, or would you abolish it all together