Modern Legal Red/Green Persist Combo Deck.
In Game 1, this is strictly a Persist Combo deck. Get any creature with the persist keyword on the field. Use Rhythm of the Wild, Grumgully, the Generous, or Melira, Sylvok Outcast to cancel out the -1/-1 counters and allow you to recur any persist creatures. Sacrifice the persist creatures with either Goblin Bombardment for full damage or Altar of Dementia for full mill. Birds of Paradise and Ignoble Hierarch are turn 1 mana ramp that help you combo off faster, Collected Company can help you dig deeper into the deck to find any persist creature or either Melira, Sylvok Outcast or Grumgully, the Generous if you need them to prevent the -1/-1 counters
Turn 1: Any green land, play Hierarch or Bird.
Turn 2: Any land, tap 3 mana for Rhythm of the Wild, Grumgully, the Generous, or Melira, Sylvok Outcast (Rhythm is objectively better because it appears less threatening without creatures on the field and enchantments are harder to kill than creatures.)
Turn 3: Any land, pay 2 for either Safehold Elite or Lesser Masticore, then pay 2 for either Goblin Bombardment or Altar of Dementia. Kill with damage or kill with mill.
In Game 2, you can transform this deck into an anti-control, anti-counter deck with Prowling Serpopard to give yourself 8 cards (in addition to the playset of Rhythm of the Wild) that say "Creature spells you control can't be countered." I would recommend siding out any combination of your sacrifice outlets (probably 2 Altar of Dementia and 2 Goblin Bombardment) since they are strictly combo pieces, and you will want to keep as many creatures as you can to follow through with the aggressive beatdown plan. Alternatively, you can take out the Birds of Paradise and the Ignoble Hierarchs, but the extra mana and the Exalted triggers on the Ignoble Hierarch feel too good to pass up.
For the rest of the sideboard, four copies of Blood Moon will shut down a lot of 3/4/5 color decks that require a heavily optimized mana base made up on non-basic lands, and in a fair amount of cases can just win the game on their own, in conjunction with the mana ramp from the mana dorks. Three copies of Wilt exist as a way to destroy artifacts or enchantments, which are the main ways of shutting down this particular deck (i.e. Leyline of Sanctity, Leyline of the Void, Rest in Peace, Relic of Progenitus, Nihil Spellbomb, etc.), and compliment the Channel ability from Boseiju, Who Endures really well for when you're in a bind against graveyard hate. A full playset of Leyline of Sanctity exist against burn decks or discard decks, and can help either shut down specific strategies or double-down on keeping your combo safe. Sideboard subject to change based on meta.