The reason why we go with Esior over the more poular Siani, Eye of the Storm is that Esior is a guaranteed turn 2 play that we can cast before casting Eligeth, providing an extra layer of protection for our most important card
It doesnt come up that often, but it does come up more often than using Arcane Denial on your own spellusing two cards to get three cards is trading a resource (cards) for the same resource (cards), which makes it not that exciting, while trading between resourcesfrom cards to mana, is more likely to get you something you need
Blue is used for Otherworldly Gaze and Tome Scour
If you like to be public enemy #1, Amarant Coral is the commander for you
If a legendary permanent or an artifact entering or leaving the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time