The powers will be unlocked with the help of a system, which helps the MC get used to the powers.
Later when he unlocks all the basic powers of Delsin In the game, The system will vanish.
So the system is just there as a tutorial for him to get used to his powers
And there will be power growth here because Delsin's Power is absorbing and copying.
In the game, there is a limit to how we can utilise his powers as there is energy needed to use any of his powers. I know in the lore He doesn't have that kind of limitation, but I am putting it in this story, so the MC won't be overpowered.
Don't worry that kind of limitation will be removed further as the story progresses, and his power will also grow and make this power his own.