Invincible wins. Even if their physical strength/durability was equal (Invincible is closer to the more elite strongmen at this point imo), Invincible's noticeably superior flight/speed and greater damage soak would give him the edge, even over Arthur's trident. The lack of long range or aoe attacks hinders him in fights like this imo.
Given Aquamans overall portrayal so far in the Nu DC..his "beating on" Superman is utter nonsense. I'm not saying you were saying it was legit, but it seems the Nu DC sometimes has some really crazy out of place instances. Do I even need to bring up what Midnighter did to the friggin Martian Manhunter? That was a sad day for comics.
As for blinding Darkseid via stabbing him with the trident, the problem is Darkseid doesn't have super speed that I know of and Invincible does. If Invincible stood there and decided to forget he had super speed..yeah, the trident could damage him.
__________________ Chicken Boo, what's the matter with you? You don't act like the other chickens do. You wear a disguise to look like human guys, but you're not a man you're a Chicken Boo.