- Location
- Hampden Park
Other than having half your physiology replaced with alien tissue? They also don't know what health problems Kon might experience in future; canonically, he couldn't grow and certainly wasn't unageing. Certainly, anyone who went through it would be infertile.Doesn't he still have most of the kryptonian/human matrix stored in his ring?
That's a pretty easy method of immortality with very few drawbacks.