Liche lord or Jadior of light...
 

Which is better for poliir?

the stats and stuff that comes with being liche lord? Or the ignore potentially 1/5th of incoming ( frontal only ) attacks, improved celestial ray, and ignore nat resist nearly 2/5ths of the time?

Jadior was pretty much designed for Paladin/Poliir, in case you hadn't noticed. Liche Lord is more of a caster race(or was. Not sure anymore).

I agree with Fenulia; Jadior of Light is much more appropriate for poliir. Although if I'm honest, the picture of an undead knight is way cooler.