What an interesting series with a real bittersweet ending, one that is just a story about revenge and how ultimately it devoured him and everything around him with a happy epilogue.
Personally not a huge fan of the reincarnated story endings if there's not build up towards it, and in this case it still doesn't really build up towards it but I feel more fine with it, but not 100% fine.
The reason why I'm not a super huge fan of those kinds of endings is because they feel extremely shoehorned in just to get a happy ending in the end. Sometimes they work, and a good chunk of the time they don't.