A willing target's appearance reverts to how it looked at the beginning of adulthood and it loses any effects of old age. For the duration, it doesn't age, cannot die of old age, and cannot be aged magically. When the spell ends, the target resumes aging at the normal rate.

The caster may optionally also choose for the target to be affected by the Geas spell with the condition of their choosing which lasts until Abra's Transhuman Infusion ends or the Geas is dispelled by Remove Curse, Greater Restoration, or Wish spell. Removing the Geas doesn't affect the other effects of Abra's Transhuman Infusion.

When you cast this spell, choose one of the following additional transformations for the target to gain:

Constructed Resilience: The target has advantage on saving throws against being poisoned, and has have resistance to poison damage. It doesn’t need to eat, drink, or breathe. It is immune to disease. 

Sentry's Rest: The target doesn’t need to sleep, and magic can’t put it to sleep. When the target takes a long rest, it must spend at least six hours in an inactive, motionless state, rather than sleeping. In this state, it appears inert but isn't rendered unconscious, and it can see and hear as normal.

Integrated Protection: The target gains a permanent +1 bonus to AC. To don or doff armor other than a shield takes 1 hour, and the target must be proficient with the armor. While the target lives, their incorporated armor can’t be removed from their body against their will.

You may cast this spell on the same target more than once but must choose a mode that the target isn't already benefitting from. When you cast this spell with a spell slot of 6th level of higher, choose an additional mode for the target to benefit from for each slot level higher than 5th. If the target ever gains the benefits of all three modes at once, the duration becomes permanent.

The material components cost twice as much for each time the target has been effected by the spell before.