So after trying it out I've decided that custom bulky talonflame sets are a real asset to any stall team. Run lefties and both STABs and roost and 4th can be SD or willo (but I prefer SD). The reason I think it's so great is it gives stall one of their only options for speed or priority. Fire STAB is also extraordinarily useful and stall is limited in options to basically heatran, charizard, maybe rotom-h, and of course talonflame itself.
Now it is not without drawbacks: rotom-w and heatran are commonly paired up and are already enough of a headache for most stall teams, but building a team around that fact and basically running 5 stall mons to take out talonflame's checks/counters or at least wear them down, is seeming to be a pretty good strategy for me. The thing is, it's ridiculously difficult to build a team that directly counters most offensive threats, so having a back up brave bird if you make a bad prediction or whatnot is a wonderful failsafe.
This is basically the best playstyle anyway: 5 stall/walls/bulk mons and 1 sweeping threat. Talonflame is an amazing pick there because of its utility against frail but powerful threats like sceptile and lopunny and greninja. It has useful resistances and immunities, too, and if hazards are down it can actaully safely switch in on a surprising amount of things.
Basically, I always try to have a fire type on stall despite the water/rock/ground weaknesses, because it cuts down on the opponents willo spam, it keeps ferrothorns and skarms away from laying hazards, and I think talonflame works well even on stall because of speed, recovery, and can ohko plenty of offensive threats while retaining EVs for bulk.
From a stall perspective there is a little bit of 4mss here because you want all of brave bird, flare blitz, roost, willo, taunt, and sd. I think the first 3 are mandatory to make it work, and willo/taunt/sd is a preference thing but I'll say again that simple SD is enough to get it done late in the game. There's no perfect set, obviously, and investing so much in HP, spdef, and some speed makes it an awfully lot weaker than the banded ones that OHKO even latios - but the compensation is the pressure you can keep on your opponent with it and the easy kills that result if you keep up hazards and status with your stallers.
edit: and here's the team Altaria / Talonflame / Mew / Skarmory / Tentacruel / Hippowdon
Altaria @ Altarianite
Ability: Natural Cure
EVs: 248 HP / 96 Def / 164 SpD
Bold Nature
IVs: 0 Atk
- Hyper Voice
- Flamethrower
- Toxic
- Roost
Talonflame @ Leftovers
Ability: Gale Wings
EVs: 248 HP / 88 Atk / 108 SpD / 64 Spe
Jolly Nature
- Brave Bird
- Flare Blitz
- Swords Dance
- Roost
Mew @ Shed Shell
Ability: Synchronize
EVs: 240 HP / 116 Def / 152 Spe
Impish Nature
- Roost
- Knock Off
- Will-O-Wisp
- Heal Bell
Skarmory @ Shed Shell
Ability: Sturdy
EVs: 248 HP / 180 Def / 80 Spe
Impish Nature
- Spikes
- Taunt
- Whirlwind
- Roost
Tentacruel @ Black Sludge
Ability: Liquid Ooze
EVs: 208 HP / 16 Def / 252 SpD / 32 Spe
Calm Nature
- Rapid Spin
- Acid Spray
- Haze
- Scald
Hippowdon @ Leftovers
Ability: Sand Stream
EVs: 240 HP / 16 Def / 252 SpD
Impish Nature
- Stealth Rock
- Earthquake
- Ice Fang
- Slack Off
Some issues with azumarill, landorus-I, and of course rotom-w but so far no battle has seemed unwinnable