Dark Souls crossover.

For centuries, Sif remained in solitude within Darkroot Garden guarding his master's gravesite, Knight Artorias, and protected his secret to his abysswalking. One fateful day during the age of fire however, an undead knight bound by destiny seeks this fabled secret, and as such, Sif does whatever it takes to prevent this knight from finding the secret… But in the end, what happens when the guardian is no more? Where does he go? And most importantly, what happens to him from there?