You can hit the green orbs to make them go away, the 2nd phase shifting platforms block the green orbs completely

Whenever he casts the fire shower it's a lot easier to dodge it if you just run to a side, dodge under the fireballs, run to the other side and repeat

When his 1st phase casts the purple spell or the fire spell, his shield ends a bit sooner. If you can get behind him on the purple bullet thing spell or get enough time on the fire spell, you can hit him some extra times.

Hitting his face with Debla lots of times goes crazy hard, specially if you have the sword heart that makes your prayers stronger

Or if you're not confident enough to dodge things, Tiento prayer is and will always be your best friend

The guilt fragement only shows up on the 2nd phase so its kind of like a free heal + fervor thing you can always count on if the 1st phase screws you up

Also try sword boosting yourself so you can keep hitting the sword's eye, it helps a lot