The best reason to be in mono-green is definitely the oversized bodies
Basilisk Gate Basilisk Gate has become the cornerstone of a Pauper archetype, but it has potential in other formats as well
Competitive Brawl Ajani, Nacatl Pariah // Ajani, Nacatl Avenger Lutri, the Spellchaser Nadu, Winged Wisdom Oko, Thief of Crowns Old Stickfingers Ragavan, Nimble Pilferer Rusko, Clockmaker Tajic, Legion's Valor Tamiyo, Inquisitive Student // Tamiyo, Seasoned Scholar Wrenn and Six Though Competitive Brawl shares many features with its Historic counterpart, like 25 starting life, a commander, and a 99 card deck constrained by the commander's color identity, it has a unique ban list of ten extremely powerful, oppressive commanders
Useful combination of attack and healing Psyburst-GX (3 Colorless Energies) 200 damage This attack's damage is not affected by effects on your opponent's Active Pokmon
1Jodah, the Unifier
Its also possible that Gengar , with its ability allowing a free retreat each turn, could be nice in a support role, but Stage 2 creatures are a pain to play, so the bars a bit higher than that in terms of utility