Whenever Borborygmos deals combat damage to a player, put a +1/+1 counter on each creature you control.
Borborygmos is a beefy 7/7 trampler that snowballs your whole board with +1/+1 counters every time he connects. The plan is to ramp into him fast, get him through with trample or evasion, and turn a small token board into a lethal army in one or two swings. You win through overwhelming, ever-growing creature mass.
Anthem-on-a-stick effect rewards going wide with tokens
Native trample means he chips through blockers and pressures life totals immediately
Counters are permanent and accumulate, so even a couple of connects create a board out of reach
Green-red gives access to elite ramp, fight removal, and aggressive token/anthem support
Seven mana and no inherent evasion beyond trample makes him easy to chump or wall
Costly to recast after a board wipe and offers no card advantage himself
His payoff requires combat damage, so fog effects, deathtouch blockers, and flyers stall him
No interaction or protection in the command zone leaves you exposed to removal and counterspells