First of all, thank you for changing Master of the Dead feat to include Death Aura.

That said, I just wanted to report it currently does not raise the caster level of Death Aura. Current description:

Your Chill Touch, Death Aura, and Negative Energy Burst spells gain +10 to their maximum caster level

Also of note, the description of Death Aura itself is inaccurate (it gives 2 to 8 + (Caster Level/2) every 3 seconds, not 2 to 8 + (Caster Level) every 2 seconds).

Anyway, using the formula that is actually used to compute damage:
[2 to 8 + (Caster Level/2)]*({Spell Power + 100}/100)

One can take a sample of ticks and find the highest and lowest numbers. This is easy to find because there should be exactly 7 repeating non-crit numbers. I did this multiple times for multiple setups, different caster levels, and spell powers.

Here are my findings:
Take 2 equations and 2 unknowns:
MinDmg = [2 + (Caster Level/2)]*({Spell Power + 100}/100)
MaxDmg = [8 + (Caster Level/2)]*({Spell Power + 100}/100)

MinDmg and MaxDmg were taken from the game as the lowest and highest ticks found from the list of 7 consecutive numbers corresponding to rolls of 2,3,4,5,6,7,8.

Solve for Caster Level, and Spell Power.

If I do this without the Master of the Dead feat, I get exactly what I would expect for my caster level (the number of wizard levels I have in a multiclass build mixed with fighter and rogue, or the 20 in the case of a pure wizard. I did both).

Then, if I do the same test with the Master of the Dead feat, I get exactly the same result as before. According to the feat description, I should have been able to solve for the Caster Level as +10 to whatever it was before, so this feat is not actually performing its duty.

This is true for the case when I had a caster level of 12, and when I had a caster level of 20, so it's not like the spell itself is blocking anything higher than 20. The feat is simply not functioning.

On another, slightly less important note, when I solve for Spell Power, I get close to what I actually have, but not exactly. It's always a little less, by an integer value, so I think some form of negative spell power is not being taken into account either.

Thanks for looking into this!