I think he gave him power, but I agree with what you're saying.
Its straight up manipulation. Tell Boruto he can't be ordinary anymore because he killed 'him' aka a God, but then plants a seal on him. So what's the truth?
Is he not an ordinary human being because he killed you?
Or is it because you put a seal on him which makes him not ordinary anymore?
Even the last page of the chapter with Boruto reflecting on the words 'You cannot be an ordinary human being' shows the seal in conjunction, which proves it.
Boruto is just a regular guy, not special in any of the slightest. He just got twisted up in a world he wasn't supposed to.
Now his future is forever ****ed.