For the past week, I've been grinding for this Worldline zero catalyst at least 80 hours non stop. I've been using all 3 characters. Everyday I've killed thousands to no avail. Going into most playlists. I noticed in all of this time. I ranked up 3 forge hammerheads. Using only the sword. Which my understanding is since I've been doing forge day one. You can only upgrade the Hammerhead using only other MG's. I know when your upgrading the hand cannons, bow etc. It will not work if you don't use hand cannons etc. So I submit, the reason why this is not dropping. Is because the servers think I'm using a MG not a sword. So I believe this catalyst is bugged. Please don't tell me I haven't doing this enough. At this point I think enough is enough for me. The most annoying thing I've been experiencing. The lack of heavy drops while I've been doing this. This is typical when you're trying for catalyst upgrade. When you're using heavy weapons. Even when you have heavy drop perk on as well as a sword scavenger. Interesting point I switched to black talon and Stryker's sure-hand and heavy's was raining down like crazy. So the program knows what I'm going for. But it's confused to what it thinks I need.