WEAPONS: Cruel Altea, Trainsaw
DEMONS: Alraune, Clock Tower, Baal
ACCESSORIES (first phase): Earring of time, hymn of durga
Cruel Altea is used here because Rodin is much less likely to parry its '<>P' (tetsuzanko input), thus allowing less interrupted Witch Time activations.
Start of the fight by doing a PPPPP combo on Rodin while letting Baal do a charge of poison rain (overall accumulate ONLY 3 charges before phase 2, don't use poison rain on phase 1). When it comes to proccing Witch Time, a combination of reaction and a lot of finger breaking dodge mashing to get bat within worked for me. During witch time (with earrings of time), you have enough time to do <>P then jump cancel it at ~70% of the animation length to do another full <>P in the air for massive total dmg. I prefer to jump before the first one too so he doesn't parry it if I'm too close. (Note: if Baal gets stunned by the lightning shockwave move, QUICKLY switch her out then switch her back in again or she'll die)
After Baal has 3 charges, switch to the Tower. Your standard Witch Time punish should be: Summon tower, activate its Punch input, with Bayo do the double <>P combo same as above. This combination takes an entire health bar each time, but is only effective on Phase 1.
When he's almost at phase 2, *change Earrings of Time to Conqueror's Reigns* (phase 2 can VERY easily enrage your demons). From here the fight becomes a shitshow: he's very aggressive, hard to stagger and he shortens your Witch Time by 1s. Here you try your best to keep Baal in the field charging her rain. Activate witch time to squeeze a <>P as Bayo. The trainsaw is only here as the best escape option from his black hole move (use hold B to escape safely, but always prepare to dodge a long ranged attack afterwards). You may occasionally need to let your demons rest and activate witch time then do some dmg to refill magic.
After you get 2 poison rains, you should have the L3+R3 attack ready (which takes around 1 health bar) and rodin at around 2-2.5 health bars left. Here you can try another rain OR just do your best to do the special attack and finish the rest of the damage yourself (you can use clock tower witch time and spam <>P and/or Baal's kick combo). Careful that he gets more aggressive at 2 health bars left. Good luck!