Although Marvel doesn't inherently do anything when it enters play without some setup, at four mana, players could take their time over the first few turns accumulating Energy counters with Attune with Aether, Woodweaver's Puzzleknot, and Aether Hub, so Marvel could eventually be activated on the same turn it's played for a potential combo win
Synergizing with the formats slower pace and multiplayer nature, Esper Sentinel can often draw you multiple cards per turn
I can't wait to put a +1/+1 counter on it with Venerated Loxodon
The Full Art version of the card features a majestic scene of Regidrago at rest near some ancient ruins, with a Lugia visibly soaring in the distance
Sure, there's no real synergy to build an entire deck around it, and yes, its as unreliable as flipping a coin three times and hoping the universe is feeling generous