It’s bugged and won’t drop if you didn’t obtain it during season of chosen. I believe it’s the only seasonal weapon that is like this. From what I can tell none of the focusing options that should drop it actually do. This bug has been reported many times on both reddit and the forums, and so far I haven’t seen bungie acknowledge it. So chances are we will never be able to obtain it. Kinda makes me mad honestly as it seems pretty fun.