Symbiotic Swarm is a 100 card Commander preconstructed deck with a counters theme, featured in Commander 2020.
Symbiotic Swarm is
Abzan colored. The primary commander is
Kathril, Aspect Warper, and the secondary commanders are
Tayam, Luminous Enigma and
Nikara, Lair Scavenger partnered with Yannik, Scavenging Sentinel.