When he starts flying around it's a wrap for me, I can't avoid him or those random lightning/fire explosions on the ground
Hell half the time I can't even get my mimic tear off in the beginning before he bodies me
You'll get him after a few more
Sounds like you just got to get the timing on those dodges for those moves.
Might be getting caught up attacking while that lightning is getting ready to drop, if so don't forget about jumping R2s.
They'll keep you moving while hitting & keeping pressure up on Bayle's poise.
Stuff that helped for me (melee):
Stayed close and dodged into his attacks/towards that injured leg, then attacking that leg.
I didn't lock-on as much because it would default at his face - but if he was flying or further away would.
For that mimic, try using the Opaline Hardtear on your flask and sipping that before you go to fight.
That way if you get caught slipping while summoning you might survive and get a chance to heal.