Anyone ever done a fire cape on a defence pure?

For sure has been done. Many youtube vids on it

unless you mean as a service, and i cant help ya there

I mean, there's someone who completed the fight caves on a level 3 account.
Without cheating like haxunit did.

It's possible, it would cost an absolute fortune though.

Maybe . Dude does some crazy stuff

used to be much easier when you were able to inflict venom with the serp helm alone.
now you would use a ring of suffering and recoil everything down.
if you cannot use ring of suffering, you will need to bring a suffering in ur inv with noted recoils. if u use a noted recoil on the suffering before ur recoil ur wearing breaks, it will reset ur recoil that ur wearing.

Prayer level? HP? Any other stats?

Its now impossible at lv 3 due to no longer stacking interfaces to tick eat

You will end at minimum level 4, so any level 3 fc accounts are the only ones forever

there is only 2 accounts that completed it at level 3 iirc