Hellbat / Banshee usually involves 1 banshee, about a dozen marines (?), 6-8 hellions, and maybe a reaper or two, correct? It's a 2 base all-in, so as long as you keep your hatch alive, you basically win.

• 15-15-15 opening is fine. Reaper harass won't be too heavy b/c they want to keep it for DPS on that push.

• It's a 1-1-1 push, so have at least 1-0 or 0-1 lings.

• Zerg static defense is really good at making bio units dead. Have a spine in front of a spore at your 3rd, NOT an overseer. Spores deal lots of damage and don't cost gas; overseers don't and do. Make them ~7:30. Spine should be transfused by creep-queens, so make your last round of new tumors after you get your lair (~6:30) so queens build up energy.

• Make lots of banelings; your gas should be going into baneling speed, banelings, and lair tech. Upgrades are optional, but definitely help. I prefer +1 attack over carapace, but that's just me.

• Surround with lings in the back -- don't let them get away from that spine / spore DPS; crash banelings into front --> hold push

• They'll probably try to doom drop you after because panicking Terran, so you can either use mutas to pick up those incoming drops, or you can: take out SCVs / squat their production with mutas, move creep queens to natural (ready to move to any base getting dropped), spore / spine your main (you can b/c you're killing SCVs and you're already ahead economically b/c failed push), and aggressively gg as they realize they've lost.

I do this everytime I go up against this build and I hold every time (well, you know... I like to think everytime.) Since you're ahead economically already, you can sacrific a drone or two for an extra spine / spore, which are obviously very very good. I don't like using roaches because they cost gas and supply when you need both for spamming lings / banelings, and they delay that extra queen. If you're going mutas anyways, leftover roaches are dead supply. Just my opinion.

glgl