You have reached the pinnacle of Necromancy and transformed yourself into a lich. Through abominable works of alchemy and surgery, you have constructed an artificial body to act as the vessel for your soul. You gain the following benefits in addition to those of your ValdaSpire24 feature.
Golem Body
Your spirit jar is your artificial golem body. It has a specific weakness, which you must discuss with your GM. Your rejuvenation is only stopped when your body is completely destroyed using its weakness. When you drop to 0 Hit Points, you temporarily die and reanimate with half of your Hit Points after 1 hour.
Gruesome Physicality
Your Strength, Dexterity, and Constitution scores become 20 if they weren't already higher.
Damage Resistance
You gain Resistance to Bludgeoning, Piercing, and Slashing damage.
Self-Stitches
You can apply any number of Spell-Stitches to yourself as a Magic action, expending ValdaSpire24 points as normal. ValdaSpire24 applied in this way last until you finish a Long Rest.