Could I get some tips for beating Trismagia?

[Morior]

I believe I'm close to beating the game by a few missions, but this 3 skulled wanker is in my way. I've attempted to beat it over ten times now and much to my dismay: I can't

I always stock up on green orbs, devil stars, etc. and I know how to use them effectively too, but I still can't.
So, tips would be extremely appreciated. Thanks!

 

[Morgan]

1. For all the faraway elemental attacks; dodge back and forth. Jump occasionally. Seriously. An alternating left-right cartwheel will make most of their attacks whiff.
2. Quick Heart on the ground to help with defense. Once fire-face comes up for his breath attack, get as close to him as possible (edge of the arena), switch to Aerial Heart and Frost Heart and DT to whack him. Keep Offense Heart on at all times and healing heart in an emergency. If he starts his firebreath aiming downwards (from you being close to the edge of the stage) he can't re-aim it if you're flying just to the side of it.
3. You can dodge the thunder head's close-up "breath attack" by Doing Absolutely Nothing.
4. Spam rocket launcher when the heads are far away, ofc.
5. ?????
6. Profit.
7. When it re-fuses its heads and does the tri-element attack just dodge roll forward.

 

[Morior]

1. For all the faraway elemental attacks; dodge back and forth. Jump occasionally. Seriously. An alternating left-right cartwheel will make most of their attacks whiff.
2. Quick Heart on the ground to help with defense. Once fire-face comes up for his breath attack, get as close to him as possible (edge of the arena), switch to Aerial Heart and Frost Heart and DT to whack him. Keep Offense Heart on at all times and healing heart in an emergency. If he starts his firebreath aiming downwards (from you being close to the edge of the stage) he can't re-aim it if you're flying just to the side of it.
3. You can dodge the thunder head's close-up "breath attack" by Doing Absolutely Nothing.
4. Spam rocket launcher when the heads are far away, ofc.
5. ?????
6. Profit.
7. When it re-fuses its heads and does the tri-element attack just dodge roll forward.

Thank you so much!

 

[devil_inside123]

Thank you so much!

When In doubt you could alternatively use DDT. that what I always did on annoying bosses, unless the full wrath of sparda on thy asses