race features:
Quasi-Lich Nature - you do not and cannot age physically. any spell or effect that would cause you to age, instead only causes your mind or soul to age. in addition you are not required to eat, sleep, drink, or breathe.
Pseudo-Phylactery - when you are reduced to 0 hitpoints, after 1d20-Con mod-prof bonus (min 2) rounds you may return to unlife at half your hitpoint max 5ft from your quasi phylactery in an unoccupied space, with no of your equipment (provided it is on the same plane of existence). using this feature has a toll on your body, mind and soul. doing this causes you to gain 2 levels of exhaustion. you may use this feature once every d6+1 days. exhaustion levels gained in this way can only be removed after this feature has recharged. while you are regenerating, your pseudo-phylactery glows on the ground, if a creature casts dispel magic at a level equal to 3+your prof bonus while you are regenerating this way, you die and cannot be revived by any means short of a wish spell. if your quasi phylactery is destroyed, you may under go a two day ritual and 50 gold to replace it.
Undead - your creature type is undead. you have resistance to necrotic and cold damage but are vulnerable to radiant
Servant Ritual - starting at level 3. over the course of a long rest, provided it is night, you may summon an undead with a CR equal to half of your prof bonus rounded down. this servant is completely obedient to you and cannot be charmed, this servant lasts until it is slain or until you use this feature again.
Alternate Healing - anytime you would be healed by a potion or spell that has the sole effect of healing you, you instead take that much damage. in addition anytime you would gain temp HP, from a leveled spell cast by another creature you regain that number of hitpoints instead. anytime a feature (that isnt a spell) would give you temp hitpoints you heal that much instead.