Longclaw, a Valyrian steel sword, belonged to House Mormont for five centuries. Given to Jon Snow by Jeor Mormont as a thank you when Jon saved his life from a wight. Pommel was changed from Mormont bear to a direwolf for House Stark.
The Lord of the Rings. Gandalf the Wizard VS the Balrog. In the end, they both die at each other's hands, but the Balrog going first, and Gandalf falling off the cliffs of Khazad-Dum to a bottomless abyss.