Session length and shape
Nightreign is run-based. A run has a beginning and an end, you either survive it or you do not, and the next one starts fresh. That structure is unusually good for a group with limited time - there is a natural stopping point every run rather than one at the end of a chapter.
Monster Hunter Wilds is a long-haul game. Hunts are discrete, but the reason to play is the accumulating project of better gear and harder monsters, which rewards a group that returns regularly. Dropping in for one evening a month gives you the weakest version of it.
If short evenings are your constraint, our short sessions guide is the more useful page than either of these.
Difficulty, honestly
Nightreign is a FromSoftware co-op game built around short, intense runs, and it is difficult by design. That is the appeal for a group that enjoys losing together and genuinely not the appeal for anyone else. If one person in your trio bounces off hard games, this will end the project.
Monster Hunter Wilds is demanding in a different way: less about reflexes and more about understanding systems. It is more forgiving moment to moment and asks more of you up front. A group that will read about weapon types will enjoy it; a group that wants to press start and understand it immediately will not.
Which suits which group
Four friends, mixed platforms, plays most weeks: Monster Hunter Wilds, comfortably. Nothing else in this genre solves the platform problem as cleanly.
Three friends, same platform, enjoys difficulty: Nightreign. It is built for exactly that shape and nothing else on our three-player page hits it harder.
Anyone else: probably neither, and Diablo IV is the more forgiving crossplay RPG for a group that wants loot and progression without a learning curve - our review and the Diablo IV versus Borderlands 3 comparison cover it.
The verdict
Monster Hunter Wilds is the better group game for most crews, because four slots and crossplay remove the two constraints that end mixed-platform projects, and Link Parties keep the same people together rather than shuffling them.
Elden Ring Nightreign is the better game for a specific trio: same platform, high tolerance for difficulty, and a preference for short runs over a long grind. It is a narrower recommendation and an excellent one when it fits.
Both sit on our co-op RPGs roundup alongside the alternatives, and if the platform split is the real problem, start at the crossplay hub instead.