dat sword? to kill fenrir? but i think Víðarr's spear that was used to stab fenrir's heart? there are also another tales that it was Víðarr's shoes was the item that used or at least contributing in slaying him... Víðarr stepped down onto his lower jaw while the holding the upper jaw with his hand and finally tear his jaw asunder, eventually killing him...
TLDR, no, sorry just dont mind it... i forgot this is a manga...