Seafloor Oracle This is our highest scoring Merfolk card that is not also a legendary to lead your tribe
In my experience, most Commander players want to win, but they're not normally looking to do it through optimization, but rather through some combination of fellowship, enjoyment, and style

Advanced Search Sets Random Syntax Aberrant Abolish Abrade Acidic Slime Acidic Slime Aftershock Ainok Survivalist Airship Crash Ancient Grudge Appetite for the Unnatural Artifact Mutation Artisan's Sorrow Atraxa's Fall Aura Shards Aura of Silence Bant Charm Bash to Bits Batterhorn Bedevil Boseiju, Who Endures Bovine Intervention Break Asunder Break Down Break Ties Broken Bond Broken Wings Bumbling Pangolin Cankerbloom Capashen Unicorn Carnivorous Canopy Casualties of War Cathar Commando Caustic Caterpillar Caustic Wasps Chandler Cindervines Citizen's Crowbar Cleanup Crew Coliseum Behemoth Collective Resistance Collision Course Conclave Naturalists Containment Breach Crack Open Crash Creeping Mold Crosis's Charm Crumble Crushing Vines Daretti, Ingenious Iconoclast Decimate Decommission Deconstruct Deconstruction Hammer Deep-Fried Plague Myr Deepfire Elemental Deface Defiant Ogre Demolish Destructive Revelry Destructive Tampering Detonate Devout Witness Dire-Strain Rampage Disenchant Dismantle Dismantling Blow Dispeller's Capsule Dissenter's Deliverance District Mascot Divine Offering Dreadmaw's Ire

Proliferate was introduced alongside infect as a way to give the mechanic more reach. The reminder text of proliferate even mentions players, so you're able to increase the number of counters on them
You have everything from removal to ramp, and even hate pieces aplenty
Real-Time Co-operative Game No turns, no waiting