
Whenever you gain life, put a +1/+1 counter on each Pest, Bat, Insect, Snake, and Spider you control.
Blech turns lifegain into a board-wide pump engine, stacking +1/+1 counters on your Pests, Bats, Insects, Snakes, and Spiders every time you gain life. You flood the board with cheap creatures of those types, deploy repeatable lifegain (especially incidental triggers like food, lifelink, or per-turn gains), then crash in for huge swings or overwhelm with counter synergies. The deck plays like a typal go-wide aggro/midrange build that snowballs out of control once a lifegain engine is online.
Add more free, repeatable lifegain (Soul Warden effects, Wickerbough Elder/Soul's Attendant variants, lifelink anthems) so Blech fires multiple times per turn cycle, and prioritize on-type creatures over generic good-stuff. Layer in independent counter doublers like Doubling Season and Hardened Scales, plus protection (Heroic Intervention, Boros Charm-style effects in color) to insulate your board from wipes. For a higher-power finish, include payoffs that convert your wide board into immediate damage, such as Craterhoof Behemoth or Overwhelming Stampede.
The most-played cards for this commander, built from aggregated deck data (the Mythic Graph). Build public decks to seed it.
→ Infinite +1/+1 counters on certain creatures, Infinite damage, Infinite lifegain
→ Infinite +1/+1 counters on certain creatures, Infinite damage, Infinite lifegain
→ Infinite +1/+1 counters on certain creatures, Infinite damage, Infinite lifegain
Combos via Commander Spellbook.
Same color identity (BG), by popularity.