It's Not A Quirk, It's A Heavenly Restriction
In a world of quirks, Izuku Midoriya heeds Katsuki Bakugo's advice and takes a swan dive.
In a world of Jujutsu and curses, Toji Fushiguro takes his own life to save his son.
Somehow, Izuku Midoriya is blessed and survives. As a consequence, His soul merges with a certain man restricted by the heavens.
Or
Izuku gains a complete Heavenly Restriction, along with the memories and experiences of a man who is very different yet somehow similar to him.
