There are a variety of weapons in [Hades], a total of 6 different weapons, namely Guan Yu - spear, Arthur - sword, Bellwulf - shield, Rama - bow and arrow, Gilgamesh - fist Set, Lucifer-Guns.
Guan Yu-Lance : Purchase the Small Prophecy of Fate List from the contractor, and then reach the final BOSS location. To reach the unlocking dialogue, you need to consume 5 Titan Blood, and then have a dialogue with Achilles.

Arthur-Sword : After unlocking Guan Yu's form, consume more than 5 Titan's Blood in the sword's weapon form, and then talk to Nyx.

Bellwulf-Shield : After unlocking Guan Yu's form, consume more than 5 Titan's Blood in the shield's weapon form, and then talk to Chaos.

Rama - Bow and Arrow : After unlocking Guan Yu's form, consume more than 5 Titan's Blood in the bow and sword weapon form, and then talk to Artemis.

Gilgamesh - Gloves : After unlocking Guan Yu's form, consume more than 5 Titan blood in the weapon form of the gloves, and then have a conversation with Artemis. You need to defeat him once with the gloves to unlock the conversation.

Lucifer - Gun : After unlocking Guan Yu's form, consume more than 5 Titan Blood in the gun's weapon form, and then talk to Zeus.
