"Kashtira" Spell/Trap cards focus on summoning additional "Kashtira" monsters, and either banishing opponents' cards if the opponent activates a card of the same type, or activating an effect when they're banished themselves
I suspect Polluted Cistern alone would already see play in EDH
While other players can stop you drawing from Esper Sentinel, more often than not, they won't want to wait an extra turn to play their spells, more or less ensuring the card at least replaces itself
The value of X is calculated only once, as Morcant's Eyes's last ability resolves
11 Cyclonic Rift By and large the most powerful board wipe in Commander, there is very little players can do to get around an overloaded cyclonic rift
"Vernusylph of the Flourishing Hills" and "Spirit of the Fall Wind"), or popularly-benevolent heavenly/celestial deities (e.g