Maedhros and Fingon...
...only the slashiest couple in the Silmarillion. Their lov-er-loyalty won them the pity and aid from the Valar, even when they were pretty mad at the House of Feanor.
So what might've been Maedhros' response to the aftermath of the Nirnaeth Arnodiad (I know I misspelled that)? He was the one who put together the plans. He was the one who roped together all the allies. He was the one who presumably convinced Fingon to join in. He was the one who employed the Easterlings that betrayed their side. And one of the major reasons he was so desperate for the fight was because he was also being pressured by his Oath to go and attack Doriath for the Silmaril Beren just stole (this back when Meilian & Thingol were still around).
But the Easterlings did betray them, and that fact destroyed Maedhros' entire host - which was about 2/3 the total fighting force the "alliance" had in that war. And of course Fingon was turned into a smear by Gothmog.
What kind of depths of despair and gloom could Fingon's death, and the guilt of his death and the general failure of the entire battle, have sent Maedhros to? How much could the results of that tragedy influence the next major event in history - the second Kinslaying in Doriath?