To push this list up in power, there are tons of cards you could load in, from Dauthi Voidwalker and Orcish Bowmasters to cards like Grave Pact, Butcher of Malakir, and Merciless Executioner
Two mana can be a lot and this eases the burden
OUT: Manic Vandal, Oxidda Scrapmelter, Tuktuk Scrapper, Captivating Crew, Insurrection, Skyscanner, Clone Shell, Hoarding Dragon, Pilgrim's Eye, Ravenous Baboons, Flameshadow Conjuring, Magewright's Stone, Mimic Vat, Barrage of Expendables, Blasting Station, Culling Dais, Helm of Possession, Anger, Rowan, Fearless Sparkmage, and Goblin Engineer IN: Arcane Signet, Burnished Hart, Fire Diamond, Patriar's Seal, Wayfarer's Bauble, Chaos Warp, Firemaw Kavu, Spawn of Thraxes, Spitebellows, Tyrant of Kher Ridges, Altar of Dementia, Demonmail Hauberk, Jaxis, the Troublemaker, Rionya, Fire Dancer, Dollhouse of Horrors, Combustible Gearhulk, Firbolg Flutist, By Force, Shattering Spree, and Vandalblast
Since it cares about counters broadly, it even has sneaky synergy with persist and undying loops and with saga creatures
There is a darker patterning on some holos and not on others