Ru is still tricky.  Who wants to facetank and has low Invo?

Hm.  Does a Gnoll gain more XP in remaining unsacrificed skills?
GnFi
sacced artifice
2x !exp
Spellcasng = 3.6
control had same.
conclusion: gnoll not for Ru.
[2020-11-03 Tue 06:51]

Mummy and Spriggan could sacc armor.  But neither can tank.

Nobody wants Ru??

OgAM is a good Ru candidate.  Could easily sacc Stealth and Dodging and even Artifice.  Og has 2nd-worst Evo score in the game.  Goes Oka first, so would gain a decent mMP bonus from pre-trained Invo.  Could probably sacc Arcana easily.  Or maybe Skill.  TSO works great with large rocks too.  So I guess it's
OgAM Oka -> Zin -> TSO -> Ru
Makes sense.
The OgAM's solution to everything is to throw a large rock at it.

BaIE is an obvious choice for +1 LoS apocalypse and sacc Stealth and low Invo, but losing Sif's +Cast hurts.  He doesn't want to close with the power leap anyway.  Whereas Ogre at least doesn't mind doing so.
[2020-11-03 Tue 07:15]

BaIE will eventually get forms that permit him to retreat at 10-speed, however.  That makes Ru more appealing.

Ru grants bonus piety for sacced skills by raw XP points, so he's better for low-apt species, and it's better to sac low-apt skills with high investment.  Skill is therefore a good first sacrifice.

BaIE will eventually get a complete spell list from Sif.

I reckon besides Skill and Stealth, Purity is an alright sac.  On average it's -1 stat, plus a malmutation.  Scream is fine with no stealth.  Shy regen hurts, but is balanced by draw out power.  No potion heal is irrelevant late game because mHP is so high relative to potion healing.

I guess it's
BaIE Sif -> Zin -> Ru

Best defense against Sif wrath is Zin's Vitalization.  Could face it while sitting on Hell:1 easily enough.

Switch to Ru quite late, since want to max skills to sac first.
[2020-11-03 Tue 20:22]