When no one was expecting it
"I will fight you old man!" Nero finally roared, completely unable to hold back his embarrassment and anger any longer. He opened his possessions box, took out his trusty dagger, and turned to fight his father.
Yet for all the growth he had experienced, for the strength he had gained, fighting against his father he was no different from when he hadn't synchronised at all. There was no substantial difference in their roles at all. The most frustrating thing was that his innate ability, which had actually upgraded once, may as well have not existed in front of his old man.
It would disappear from Nero's control as if it weren't his ability to begin with.
"You unfilial brat! If you absolutely had to get a tattoo, then you should have tattooed my face onto your back to thank me for bringing you into this world!"
"Old man, you won't always be stronger than me! Watch out for the day I throw you in a disabled elderly home!"