Raiden would be incapable of hurting Thor, Thor would be incapable of hitting Raiden. Stalemate.
The Nidavellir feat lowballed to its absolute lowest end, which is to say if only moved a single pixel onscreen due to Thor himself, would make him much stronger than Raiden and Armstrong combined.
You're either delusional or trolling, but even if we ignore the strength difference in favor of Raiden, he has a HF blade that can cut basically anything and Thor has terrible slashing and piercing resistance feats. Odinson gets shredded.
Looking at all Thors feats and then Nidavellir makes me absolutely certain Raiden can replicate it and probably for much longer. He is so far above Thor in strength and durability feats that if Thor can do it, Raiden can with ease. Thor can't even punch out Hulk when Hulkbuster, Abomination, and Thanos have all put him down. Raiden on the other hand is casually slinging around hundreds and thousands of tons without breaking a sweat.
I wanna point out we NEVER saw the full extent of Raiden's strength. His pre-upgraded body stopped Outer Haven and threw a Metal Gear, but his post-upgrade body... we just never saw what it's fully capable of.
He never seems to exert himself too much in the strength department. It's likely that Metal Gear was like lifting a 50kg weight to him.
Every Gear he threw, he did it with not above a normal degree of effort. Even Exelcus he just turned and chucked it. It took like 3 seconds.
Also him using one of it's saws like a building sized sword and swinging it at the speed he did is just insane. Just lifting it and moving it by itself is crazy, but he was swinging it at speeds to match the robot while being like less than 1% the size of it.
Why? Getting cut by Loki could be a low feat, but Hela is stronger than Thor, strong enough to shatter Mjolnir with one hand. Mjolnir, which was forged in the heart of Nidavellir. She's also much stronger than Raiden.
Do you have a single feat from Raiden on par with the Nidavellir feat? This is a rhetorical question, I already know for a fact that you don't. I'm much more familiar with Raiden's feats than you are, as well as Thor's.
You said it yourself, Loki cut Thor with no effort. Raiden blows Loki out of the water in strength feats. Why on Earth would Raiden be unable to cut Thor? .
Yeah the Nidavellir feat makes him much stronger, however, the Excelsus blade feat and his durability should make him strong enough to be able to block or parry Thor's blows without dying. He's much faster then Thor when it comes to reaction times and on-foot movement speed, it's the flying where Thor might be a bit faster, though not by much.
I'd also say Raiden's punches can hurt Thor.
Thor's lightning won't do much, I don't think lightning can hurt Raiden after he was hit by it directly and all it did was conduct through him.
I'm not sure if getting the Bifrost involved will change anything but we'll see.
Let's not forget Thor has stuff like TK on his side, meaning he won't have to get super close unless he has to. But since he's in-character, he'll probably try to get up-close and personal.