Originally, Rio already had 'true immunity' to defend against charm attacks, illusions, and other things.
But he wasn't immune to poisons and other physical de-buffs like curses, infections, etc.
Now that he has the 'Imperfect Sword Heart', he doesn't need to worry about all that; he can drink the most lethal poisons of this world like normal juices.
But this also has a side effect.
Rio will never be able to get drunk, even if he wanted to, because alcohol will have no effect on him.
'Not like I ever want to get drunk… I like tea more than alcohol anyway..'
While Rio was busy thinking about his newfound powers, Ryul came back, and a look of surprise hung over his face as he asked,
"D*mn boy, what did you do? How did you create such a strong spatial fluctuation just now?"
At Ryul's words, Rio tilted his head in confusion.
"Spatial fluctuation?"
Seeing that Rio was confused, Ryul concluded that he likely didn't know about it.
