after going for roshi, i'd reccomend for gnw(with the full 300 seals in the seal rebate) to eventually get edo hashi, which is still popular in cn. DON'T go for edo minato, he svcks, his damage is little, his mystery has a 3rd cooldown, and he has no scaling. I'd recommend the other 2 minatos.

EDIT: proof his damage is low

https://www.youtube.com/watch?v=qx8G8M9YBdc watch the first fight closely, his edo hashi did more damage in his lineup compared to edo minato who is probably stacked due to him being pos 1, and the damage edo minato deals is low. If you're a fan of minato, i'd suggest picking up HK minato, or jonin minato(he'll be really good after the bond update plus the release of 5 kage madara.