@jjnor he imitate the ability recreating in such way that made it his own. A big example is the aura attack that he was practicing to stop someone from moving the other guy aura is wind and thunder but the protagonist can't do that but he could recreate it imitating it so he create that movement in where stops you w some kind of spider webs instead of wind and lightning etc

@Red_August yeah also the past life gave him cat g** reflexes and keen senses  just remember when he fought himself. 
How easy his older self was adapting to his younger self so he is practically someone older in spirit in a young body w enough experience to be able to learn something new from experiencing it a couple times .
Its a bit ridiculous but he didn't recreate the ability he just imitated using his own abilities.

@Red_August yeah also the past life gave him cat g** reflexes and keen senses  just remember when he fought himself. 
How easy his older self was adapting to his younger self so he is practically someone older in spirit in a young body w enough experience to be able to learn something new from experiencing it a couple times .
Its a bit ridiculous but he didn't recreate the ability he just imitated using his own abilities.

@Red_August he was not transcendent  he was once human too and obtained  power . So its not impossible for him to reach that level one day  but what he did is just imitate not recreating