Favored Soul casters levels are a hot mess.
One thing I want to point out right up front, there is a particular thing that is definitely not functioning as intended and if they start cleaning up casters levels they might stumble upon this and fix it. It's nothing Earth shattering and it's absolutely not an exploit because it works the way it works and there's nothing anyone has do to make it do this nor is there anyway that anyone can do anything to avoid it. If you are intimately knowledgeable with FVS, especially at end game in high difficulties, and know what I'm talking about and think this is more important than any caster level mess then I might be inclined to agree. With melee cleaving away at a roomful of baddies for tens of thousands in damage in high reaper levels, this particular thing isn't even a blip on the radar, so when I say it's nothing Earth shattering it really isn't, but it certainly might be more beneficial than everything below combined.
Alright, so I have a first life pure FVS at cap. He's the original toon I ran the original level 20 cap epics on as a healer. He was parked at level 25 and I haven't done anything with him since. Pretty much right around the time I figured out that positive spell power wasn't being fully applied to Heal/Heal Mass, a stealth nerf that really didn't make any sense but was later confirmed by devs as working as intended after I drew attention to the discrepancy. They updated the tool tip to reflect this nerf with some pathetic excuse about wanting to make cure spells more important. Only 50% spell power is applied to Heal/Heal Mass. Well I just capped this character and have been running around Barovia having fun checking out the new (to me) content. As I was leveling him up I chose an epic feat called Master of Light, which increases the max caster level of Sun Bolt, Searing Light, and Divine Punishment by 10! I couldn't wait to get into a dungeon to unleash this new found power, except, Sun Bolt damage was the same. I started looking at caster levels and figured it must be something to do with the fact that Angel of Vengeance awards +1 Caster Level and +2 Max Caster level for each core ability, so that's a total of 6 caster levels and 12 max caster levels... granting 6 more MCL than CL. I didn't think much about it at the time, and moved on with leveling and playing.
Now, at cap with a destiny with max XP, I've decided to ETR to fix the build, getting rid of Master of Light among other things. Except I wanted to ensure I was doing the right thing so I started digging in to casters levels to make sure I wasn't making a mistake, what I found was FVS caster levels are a complete mess and almost nothing is what it should be.
Caster Level
My character is a level 20 pure Favored Soul, so that's caster level 20.
My character has all 6 Angel of Vengeance core abilities for +6 to caster level with sun Bolt, Nimbus of Light, Searing Light, Cometfall, Flame Strike, Fire Storm, and Divine Punishment.
My character has the AoV enhancement Intense Faith for +3 caster level with all fire, force, light, and physical damage spells (which would apply to all of the above named spells).
Therefore my character at level 20 should be casting all of the spells listed above at level 29 except where limited by Max Caster Level. My character has +15 MCL though from AoV enhancements. 12 from core abilities, and 3 from Zealous Faith.
Max Caster Level
Sun Bolt - A powerful bolt of light deals 5 to 8 light damage per caster level (up to a max of 75 to 120 damage at caster level 15) to targets in its path. A successful Reflex save reduces the damage by half. D&D Dice: Deals 1d4+4 light damage per caster level (max 15d4+60). So Sun Bolt is MCL 15... except with my AoV boost it should be MCL 30.
Searing Light - Focuses divine power like a ray of the sun, causing a blast of light to deal 1d4+4 light damage per 2 caster levels (Maximum damage 5d4+20.), or deals 1d3+3 light damage per caster level to Undead. (Maximum damage 10d3+30.) This one is strange, as it's MCL is 10 against undead, but it only benefits from every 2 levels for living creatures yet maxes out on an odd number, 5. It's difficult to be certain of it's intended MCL, as it doesn't state a MCL but instead states a max damage. I understand why this one is messed up because it's very ambiguous, but it appears they just take the MCL for undead and halve it. So with +15 from AoV it should be MCL 25 against undead and half that for living... so 12?
Nimbus of Light - A glittering corona of light coalesces around your outstretched arm, dealing 1d4+4 points of light damage plus 1 additional damage for every caster level. This ray has double spell range. This spell has no max caster level.
Divine Punishment - Focuses the power of the gods upon the target, inflicting 1d6 +1 light damage every 2 seconds (no initial tic) for a duration of 16 seconds (at CL1). This damage scales by +1 per caster level light damage up to a maximum 1d6+20 at caster level 20. MCL 20 + 15 from AoV = 35.
Comet Fall - You conjure a bright, glowing comet, which appears in midair above your target, then strikes the ground with tremendous force. This area of effect spell does 2d3+6 points of bludgeon damage for every 2 caster levels (Maximum 20d3+60 at caster level 20). A successful Reflex save reduces the damage by half. MCL is clearly stated as 20, so +15 from AoV should increase its caster level to 35, but it only does increased damage for every 2 levels so at CL 35 it would do 17 x 2d3+6.
Flame Strike - Here the wiki does not agree with the in game tool tip, therefore I'm going with the in game tool tip as it specifically states 1d3 per caster level max 30d3. So Flame strike has a MCL of 30, with +15 from AoV it should be MCL 45.
Fire Storm - I don't have it, therefore can't test it.
Theory
OK, now we know that my character has a caster level of 29 so let's look at each spell to see what level my character should cast it at...
Sun Bolt - 29
Searing Light - 25 (against undead for sure)
Nimbus of Light - 29
Divine Punishment - 29
Cometfall - 29
Flame Strike - 29
In Exalted Angel for every core ability past the first one you get +1 divine caster level, for a total of +5. So in EA my character should cast at...
Sun Bolt - 34 (would be capped at 30 except for Master of Light epic feat that raises Sun Bolt, Searing Light, and Divine Punishment by +10)
Searing Light - 30
Nimbus of Light - 34
Divine Punishment - 34
Cometfall - 34
Flame Strike - 34
Master of Light Epic Feat
This shows that in theory the ONLY THING MoL does is allow ONE SPELL, Sun Bolt, in Exalted Angel to increase its caster level from its MCL of 30 to 40 which then allows it to go from CL 30-34 while in the EA ED. I just don't understand why this "EPIC" feat even exists? Even if you aren't in the Angel of Vengeance enhancement tree for the +12 to MCL, you also aren't getting the +9 to CL from that tree and therefore likely won't need any MCL boost anyway!
In reality, I'm not sure what is going on as you'll see below.
Reality
This part gets tricky as it's pretty messed up.
At cap, while already in the Exalted Angel Destiny before logging in, here's the actual caster level of the spells:
Sun Bolt - 32 (34) -2
Searing Light - 35 (30) +5
Nimbus of Light - 35 (34) +1
Divine Punishment - 35 (34) +1
Cometfall - 35 (34) +1
Flame Strike - 32 (34) -2
Overall, most get a tiny increase in caster level over what was expected. However, Sun Bolt, the most powerful spell, is 2 less than expected, and as mentioned above it's the ONLY spell that theoretically benefits from the +10 MCL of Master of Light!???
The story gets even stranger though. After changing from Legendary Dreadnought, a completely empty ED for this character, without logging out, I got caster level 32 for all the spells except Flame Strike which was 29. CRAZY!!! I'd understand if the caster levels were all 5 less, because then it would just be an issue of it not adding the +5 from EA, but Sun Bolt is the same and the others are only 3 less. Just weird, but it gets weirder.
If you change from EA to LD you get 32 for Sunbolt 27 for Flame Strike and 30 for everything else. So that's 5 less for all but Sun Bolt?, which remains unaffected, just as you would expect. Except if you log out and back in, they all drop by 1, except Sun Bolt, which again remains unaffected.
Conclusion
I don't know what is going on here. Nothing is way off, so it's not the end of the world, but Sun Bolt doesn't seem to be affected by EA at all, which is quite odd. The strangest thing of everything is Master of Light, an epic feat which doesn't do anything at all!!! It should very slightly benefit a single spell, Sun Bolt, but NOTHING affects Sun Bolt! Master of Light should be changed to +10 CL and +10 MCL, then it would actually do something! Before you start screaming how OP that would be, go watch some videos of a barbarian running R7 solo and cleaving away for tens of thousands in damage all while being automatically healed by a constant stream of +300.
So as it stands, the take away I get from all this is just don't waste a feat on Master of Light. All the caster levels are a little wonky, but nothing is incredibly out of line, and there's one small benefit from something that isn't working as intended that might get fixed if they fix everything else.
I'm about to ETR, and this time around I'm not going to take Master of Light. I'm going to test all of the above as soon as I log back in at level 20, before taking any enhancements, well Sun Bolt is granted by enhancements, but I'll test that at the minimum level of enhancement and then as I take each core ability and each point of Intense Faith. Then I'll try to format all the numbers in a more easily discerned manner and report back.