Being able to put a massive restriction over which cards your opponents get to tutor can be absolutely game-breaking in a tutor-heavy format like EDH
Since Kefka, Ruler of Ruin has flying and is pretty tough, you can also likely attack with it to draw some extra cards
Several other cards allow for extra draw or the return of cards to the hand, keeping an Amber/Amethyst player well-stocked and ready to keep the table full
3 Cyclonic Rift Is One Of Commander's Saltiest Cards, Board Wipe Or Not Cyclonic Rift, according to some sites, ranks among the Commander format's saltiest cards of allthat is, it greatly annoys the other players anytime it's cast
A few of these cards just might not work in play, and some others will slip under the radar until played in the right deck
This is one of those cards that will take off when a dedicated deck-builder finds the right build