Hidden/Spoiler:
Solution: I fixed this through hexediting. This artifact is caused by one of the following MODL chunks: hp_b_chuck, hp_f_chain, hp_b_chain, hp_f_chuck and hp_chain. These all look like they're related to the original DLC weapon Ventress uses. I just removed them from the msh file in one go and now the artifact is gone (So far, I haven't noticed any negative side effects to doing this). If anyone else wants to do this, find the above MODL chunks following this tutorial and remove them. Then change the HEDR size to 174,444 and the MSH2 size to 170812 (the total size of these MODL chunks is 660, so the new MSH2 is just the old MSH2 - 660. Finding the HEDR is even easier. Put your cursor on the very last byte of the modified msh, read the address then subtract 7. That should work for every hex edit, because the HEDR always tells you the overall file size. HEDRXXXX is 8 bytes so you subtract 8, but the addresses start at 0 so you add 1 back on).

