This is "Night sky sword" from the book series Sword art online, Book 7 was it? Alicization. It's a sword made out of the branch of a giant black tree, used by Kirito during this books events.
V2.0 Yet another rewrap...
V3.0 Remade the whole model reducing it's filesize in 48kb aprox and rewraped it again.
V3.1 Changed internal name and added frames, bones and one animations that does nothing to make it visible.
V3.2 Rewrapped and changed screenshot.
V3.3 Rewrapped again, changed screenshot.
V3.4 Rewrapped again, changed screenshot, added a geoset.
V3.5 Rewrap. Was to lazy to update screenshot. Made some other small changes again, so small they will be put together with this one.
V3.6 Hopefully centered the wrap and improved it.
V4.0 Remade the handle, reduced filesize, had to wrap again...
V5.0 Changed facing, resized like 10 times (I still think it looks too long...), and mostly worked so that it looks like an attachment.
V5.1 Rewrapped handle, centrated guard, made symmetric, straighten the edge, removed 1 more vertex.
V5.2 hopefully centered and fixed everything...
V5.3 removed some weird brown things that where showing in the texture and which I somehow hadn't seen before.
V5.4 Remade the description of the model.
V5.5 Re added animations