Trouble with Infernal base final fight

I’ve been trying to beat this fight for hours, I have made a functional strategy despite my awful team levels (the game levels hiked way too fast and my venusaur carried)

Here is my current strategy:

I lead with typhlosion and use flamethrower, this puts the opposing excadrill below half, in order for this to work the excadrill HAS to use swords dance, not rock slide or earthquake, if they do I reset (1/3 chance)

next they have to use a full restore, this is garunteed if I burn with flame thrower but sometimes he will full restore when he isn’t burned (seems to be about 1/3 too)

then my typhlosion uses flame thrower and dies next turn, if I get a crit then I have to reset, after he dies to the rock slide or earthquake I send in venusaur, mega evolve, and moon blast, this gets me 1 stage in spa, next he sends out chandelure who I one shot with psychic and get 2 stage boost (seems to be garunteed, hasn’t failed at this stage yet)

The next problem pokemon is volcarona who is garunteed to quiver dance turn 1, I have tried using thunder wave for the para which does work but I don’t believe I can win from that position, instead the only strategy that works is thunder bolt on venusaur, it hits neutral unlike psychic or moon blast, if I get a high roll (it has only happened once and that was my closest attempt) if I get a paralysis, or if I get a crit (seems to work about 1/10 times)

the next problem is speed boost mega blaziken, if my venusaur is at full health (got a para and full paralysis the volcarona or got a high roll crit) then I can just use psychic and he dies, the heatran is the most annoying pokemon and has ended the most runs, my current strategy is using bolt, dying, swapping to mew and using thunder wave then spamming him with all my pokemon until he dies.

Using this strategy I have managed to get his last pokemon to red twice, still trying to win

note: I could technically farm using exp share and killing the excadril but it is insanely slow and I really don’t want to, I’ve already beat all trainers and I have no other pokemon even close in level to my main team shown here, I do have delta pigeotto which has intimidate, maybe I could swap my breloom or haxorus or one of the useless back mons for it to weaken heatran in the final stage

also, I can not let excadrill die to typhlosion, that is why if I crit I have to reset, I have to drain the full restore to make the final heatran stage possible and I have to weaken him enough for mega venusaur to get the SPA boost

also also, I have to be in normal mode to do this strategy, in hard mode the perfect ivs and evs makes it too hard and in easy mode the next mon he sends out after excadrill is heatran, which ruins my strategy as it beats mega venusaur

I finally won after 4 and a half hours