Indeed, this is not a soap opera... or so he tells to himself when not stopping her wedding with some other dude.
He just lets her get banged by that man for 5 years when he's breaking the hearts of 100 other girl for their "promise", even the loyal one that truly loved his man-slut ass.
Also remember this is not a soap opera so him jumping down a cliff and surviving it's completely normal. And being so rich that he can buy the company of the husband of his love interest and "save" her after that is also normal.
Yeaaaah, imo those last pages are just his dying hallucinations, no way dude became richer than the other dude from thin air.