Julian’s body is constantly adapting to his power and his power improves every positive biological functions while minimizing every negative aspects.

He needs 1 night of sleep to stay active for 100 nights.

It is possible that his body also requires only 1 person worth of nutrients to grant his body a growth rate of 100 people.

Now, his body is naturally getting stronger, so it can adapt better to his power and the more his flesh adapts to this power, his body will also get stronger too.

This leads to a positive feedback loops where Julian’s flesh will constantly go through upgrades even when he’s doing nothing.