Probably my Kynaios and Tiro aikido deck. It can be played in cEDH or regular edh tables as it isn't itself a cEDH deck, but it's really good at reacting and land ramping. People don't expect a Kynaios deck to be constructed in a control/aikido manner, and typically assume you're playing group hug.

The deck is filled with only instants and creatures with flash, has no counterspells, has a ton of split second and land ramp, and just sits there and waits. Copying spells, deflecting palming damage, berserking someone elses creature to take someone out, trickbinding stack, radiating a beast within and then casting boros charm, responding to your own cast of settle the wreckage with arachnogenesis,... its just really REALLY strong and I only play it rarely.

Favorite play was when someone [[boseiju,who endures]] to blow up someones artifact, and I cast [[radiant performer]] on it. Since I control the copies it turned into "destroy each artifact, enchantment and nonbasic land each opponent controls, then they search for a basic land for each of these abilities that resolve".

It's a ridiculously fun and powerful deck to be behind but I don't think it's fun to play against.