[Yregwyn]

Fingy was beside himself with rage and grief, he was so mad and heart broke that he wasn't thinking clear. Ive seen alot of people get so mad they do stuff that they normally wouldn't do. I have been in that situation myself. This is the case here he was so mad his "eyes shone like the eyes of the Valar". He was in such a rage that the only thing he could think about was hurting Morgoth anyway he could. I agree with Inziladun. Eomer was in a similar situation on the Pelennor, the thing that brought him out of it was seeing Aragon's standard with the fleet. He was already arraying his troops in a shield wall to fight to the last on foot when the black ships came. I dont think either of them wanted to die, but that wasn't a concern. The main thing that they both wanted was to hurt the enemy as much as possible.