Hidden blade (every type of kill with them possible.) Double swords Single sword (off a guard) Throwing knife (both owned and disarmed off a guard.) Heavy weapon disarmed off a guard (regular kill and special kill.) Berserker dart (both being killed by other guards and time running out.) Rope dart (pull towards, choking and hanging.) Unarmed Pistols Rifle from guard, both shooting and bayonet Swivel gun on the Jackdaw I even made a brute kill himself with his own grenade.
These are just off the top of my head and I may have forgotten some. Someone mentioned it isn't a glitch and I am missing something. I am all for that but what am I missing?
Ah... Amaterasu. Origin of all that is good and mother to us all... GT,PSN: STBadly
I had the glitch that made it stuck at 8/9, but with the last patch it was fixed. Anyway, before that, there was a workaround.
Go to the save data and delete your profile data. NOT THE SAVEGAME, but the profile data. Next time you start AC IV, you should get the "5 statues" challenge notification, and, assuming the weapons challenge wasn't counting, it should now count. Beware that it may still appear has incompleted, like 8/9, but if you look at the total challenges completed it may have 1 more completed. It's what happened to me. I actually had 100 challenges completed, the last cheat awarded as well as the multiplayer title, but the weapons challenge was still 8/9. With the last patch, it changed to "completed".