The majority of Japanese games with a NTR tag is just that. Netorare, not netori, meaning the protagonist (or the male character) gets cucked in some way.
Switching the protagonist to Brad...basically makes it a new game tbh. Different focus entirely. There are a few games but those are in Japanese only.
If you're interested in a netori game, your best bets are to look under the cheating tag and find western games. Most are in RenPy and use 3D models though. As far as I remember for rpgm games, I would think Nobleman's retort(hypnosis), Amor Magic Academy (kinda), and Urban Demons are ones where you can cuck other people. There are a couple visual novels out there that are translated if you're interested. But you'll probably be hard pressed to find a translated japanese game where you get to play as the alpha.
Haha that is so true lol. Tbh i kinda expected this answer since i already search to the best of my ability but hardly found anything 2d that fit what i wanted. I just asked hoping there's a slim chance i missed something. Actually there're quite a lot of netori japanese games on dlsite it's just that people like cheating female protagonist game with rape on defeat and dense cuck male protagonist more so not sure if netori games would ever get the translator's attention. Heck, netori aside finding a translated vanilla rpgm with male protag is already quite a chore.
I tend to avoid western 3d games since they're usually patreon games thus unfinished, focus on too many kinks at the same time such as furry, futa, lesbian...while lacking my type of kinks which is ahegao and xray(cross-section) view, both usually found in ntr lol. Urban demon looks nice tho so i'll probably check it out despise the 0.11 beta ver which probably doesn't have very much content yet.
Nobleman retort while focus on hypnosis, not the vanilla netori i'm looking for is still quite hot, especially the blond wife. Armor maho academy tho is a fuckfess and the protagonist is considered inferior to other male characters in the game so it's still pretty damn depressing.
About Shadowcore, i totally can imagine the game turning into vanilla netori with Brad as the protagonist since there's no need for blackmail, drugs, rape or hypnotize to steal Elishia from someone like Mist, not when Elishia is already slutty from the start lol.