How do I calculate the the CR adjustment when adding Divine Rank 0?
Note: Yes, I know that not everyone agrees with the CR but it is a useful overall guide. So, with that being said I need to make sure I don't completely murder my PCs.
Related: This Question is similar but it's asking a completely different question.
I will have a 20-HD enemy (main boss) that will be granted divine status at Rank 0 while he is doing his bidding. (with the promise of higher status once complete.) I would like to make sure I place the encounter that is atleast possible to win.
(I am planning to have the party be lvl 18)
Divine Rank 0 gives some, but not all of a god's benefits.
A quick rundown of quasi-deity abilities
There are many more abilities that they do not get until rank 1 which I didn't list since they don't apply.
Deities receive maximum hit points for each Hit Die.
Deities can move much more quickly than mortals. (Medium biped: 60', 30 climb, 120 Fly if capable)
For every 20 extra ranks a deity has in a skill, the deity’s synergy bonus from the skill (if any) increases by +2.
Immunities Deities have the following immunities. Individual deities may have more immunities. Unless otherwise indicated, these immunities do not apply if the attacker is a deity of equal or higher rank.
Transmutation A deity is immune to polymorphing, petrification, or any other attack that alters its form. Any shape-altering powers the deity might have work normally on itself.
Drain: Energy Drain, Ability Drain, Ability Damage A deity is not subject to energy drain, ability drain, or ability damage.
Mind-Affecting Effects A deity is immune to mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects).
Damage Reduction: 10/epic
Fire resistance: 5 + divine rank (0)= *Fire Resist 5
Spell resistance: 32 + divine rank (0)=SR 32
Immortality: All deities (even those of rank 0) are naturally immortal and cannot die from natural causes. Deities do not age, and they do not need to eat, sleep, or breathe. The only way for a deity to die is through special circumstances, usually by being slain in magical or physical combat.