Assuming a lvl 20 Twilight Sage dies, while dead with an arcane pool, they can cast spells. Could they use the class feature Twilight Transfer to come back from the dead? If no, could they use a standard breath of life to come back? Can they use any spell while in this dead ghosty form to come back?
I would say no to Twilight Transfer as it requires a touch, and the capstone Death release says "The spirit can't move, deliver touch or ranged touch spells, or do anything that isn't part of casting a spell." and Twilight Transfer is an SU ability and requires a touch.
As far as breath of life, well you'd need to have it on your spell list, and it's touch spell, so no on both counts.
The question comes down is there a spell on the arcanist spell list that could revive you from the dead.
Hmm. You could make yourself undead!