[SPOILER WARNING] How to beat Eviterno, The First of the Pentients
HUGE SPOILER WARNING!!!
First Things first, Get your loadout ready. Lucky us, you are able to switch rosary beads whenever you pause the game. My loadout was as follows.
Altarpiece: The Pillager, The Punished One, Unwavering One, Cobijada Mayor, The Traitor, Nacimiento, The Selfless Father, The Woman of the Stolen Face (This is IN ORDER starting top left to bottom right.)
Rosary Beads: Pewter Tears, Scratched Face from the Canvas, Votive Offering Claimed by Rust, Imprint of Scalopendra, Sphere Kissed by the Storm.
Prayers: I did not find myself using a Quick Verse, but I strongly recommend using the Debla of the Lights chant in the first phase and Seguiriya to the Memory of your Eyes in the second.
Additionally you are also going to want to be using a fully maxed out Ruego Al Alba simply for the damage and its air moves. Veredicto is too slow and Sarmiento & Centella are simply too garbage to be used for any reason in this game. Make sure NOT to use Blood Pact (unless you are in stopped time) it is not worth it to lose that much health for some damage.
Strategy P1
If you have a maxed out Prie Dreu then you should start off with maximum fervor. When he flies upwards to charge up the sun attack, use Debla of the Lights. When the sun hits the ground Double Jump upwards and dash towards the center. If you had enough air time the attack shouldn't hurt you. When he is using his thunder orb attack, dash straight towards him and use Debla. When he is doing his teleport thunder orb attack, slide under him as he fires and use Debla after the last teleport. When he uses his thunder beam attack, AIR DASH through them. It is easily his worst attack in this phase. Repeat until he is dead. Try to take minimal damage as the second phase of this fight is at least 10 times worse than the first.
Strategy P2
I don't recommend going for blocks in this phase especially since we have the dodge cooldown Altarpiece. He has a set pattern that you can recognize if you look closely. First, he will dash forwards with the upwards slice. You can punish this quick with one of two hits by dodging through it, but make sure you aren't too close to him because the hitbox wraps around his whole body. He will then teleport and do a quick slice at your feet, just jump over this and don't try to hit him. He will the charge up a powerful upwards slice that leaves a large shockwave. Double jump until you are about halfway between his initial slice and the shockwave, then dash towards him. This is when he is most vulnerable. This is where you want to either Heal, Attack him 4 times, or Time Stop. He additionally has a small sword beam attack that you can just jump over. After this he will teleport. Sometimes he will do a large jumping lunge attack. This is his most punishable move but he doesn't do it often during this phase. Air Dash through him while he is in the airand start attacking him from behind. You can use Debla here or you can heal as well.
Strategy P2.5
Here is where the fight gets a tinge more difficult. He will begin doing a large circular slash in mid air. Slide away from this and when the slash is over slide back towards him, he will be open for a couple more seconds. Get a couple hits in, and back off. Sometimes his upward slice-dash will be comboed into the air, where he will lung towards you slightly and slice, and then slam back into the ground similar to his jumping move from the first half of this phase. Both of these moves can be punished heavily, but stay focused because you are right near the end of this tough fight.
The Summons
He will slam the crimson binding into the ground and create a black-red beam. This teleports you into a dark room. First, Orospina will use her lightning dash across the bottom of the screen. Jump over this. Lesmes will use his flame pillar slam, this time extra fire beams will appear to try to dash away. Infanta will appear next, and she will use her Miasma thorn ability. It doesn't deal much damage, but just run to dodge it and dash if need be. Next, Benedicta will summon her towers, just air dash through one of the small holes they make while falling. Finally, Odon will use his forwards dash slice, just double jump and dash over this. Finally, the move will end with Eviterno using his circular air slice right in the middle.
Home Stretch
Only thing different about this final section is that he will begin using the shockwave creating move whenever he wants. Other than that, just keep calm and you'll be finished with this extremely hard fight to end off this amazing game. Hope I was of some help and if you guys think you have any changes to my strategy lmk.