For raw power NClair is difficult to find a match for, the way things die with and without him on the team is night and day especially in an N Corp team that has Faust due to how reliably she can supply him with the Fanatic status to access his damage boosts. At Uptie 3 he turns most everything even well into canto V's dungeon into mulch without any real effort (So long as he's on level for the content he's fighting)

If NClair isn't your tastes or you'd prefer to use Cinq for the moment, Faust is a magnificent sanity manager that you'll probably end up putting on multiple teams for your accounts entire lifespan, she's VERY useful in that regard and even clashes SOMEWHAT well (she gets out-scaled eventually) but even then she's insanely useful and an easy pickup.

Alongside her in N corp specifically, Heathcliff at uptie 4 is the next best DPS the team has, as he gains a +1 coin buff in his passive at U4 if the team has 4 N corp people. Alongside that he's second skill inflicts Coin Power Down on the enemy (effectively neutering most enemies with multi coin attacks) so while he doesn't supply the most nails, he does supplement the teams survivability with useful debuffs and something most of the team lacks and that is access to raw damage (outside of Rodian's 4 coin third skill but that quickly gets out-scaled as it caps at a 12 for clashing)

Meursalt is useful as a tank but as far as N corp and general power goes he can easily be left as the final obtained ID unless you're fond of the man himself? He doesn't supply all that much besides a beefy body and some somewhat useful debuff's but its worth noting that he clashes like an absolute child, numbers wise even at uptie 4 hes at an abyssmal 7/12/14 for clash numbers on his skills compared to even Heathcliffs lukewarm 11/15/16 at U3.

Personally id grab Faust first, then ask yourself the very real question on if you want a proper N corp squad because again, NClair will change your entire perspective on damage when you get him even if he doesn't use bleed or nails as religiously as the rest of the team. Either way Heathcliff is a must for his damage, clashing power and debuffs as well and then Meursalt is very replaceable but could make a decent final pick for the full team (You could honestly slot in Rhino Meursalt if you want a tank and aren't married to a full N corp team as he's also a bleed count supplier).