The weapons used by Zagreus in Hades were originally used by his Olympian family in their ancient battle against the Titans. This is why these weapons have a taste for Titan Blood, but unfortunately, the lifeblood of ancient super-deities isn’t exactly readily available. You can get all the blood your weapons crave, though, you just have to know where to look.
How to Get Titan Blood
In any given Hades run, you have two opportunities to get a shot of Titan Blood: one from defeating one of the Furies at the end of Tartarus, and one from defeating Hades at the very end. Each weapon offers a separate bounty board, so you can get two more shots for each weapon you clear a run with.
However, what are you supposed to do when you’ve beaten Hades with every weapon? Simple: punish yourself! After the first time you beat Hades, you’ll gain access to the Pact of Punishment. Using the pact before you start a new run, you can place restrictions on yourself to increase the run’s Heat level, and for every Heat level, you get a fresh stack of bounties. That means two more shots of Titan Blood for every Heat level.
Aside from run bounties, you can also get more Titan Blood from the Fated List of Minor prophecies, which yields them as rewards when certain prophecies are fulfilled. The Wretched Broker in the House of Hades Lounge will trade you a Titan Blood for one bottle of Ambrosia, which you obtain from defeating Theseus in Elysium.
The Wretched Broker may occasionally offer different deals that yield Titan Blood, but the Ambrosia trade is usually the easiest to accommodate. Occasionally, Charon will sell you Titan Blood in his store in the Temple of Styx, but the cost is usually massive, and that money is better spent helping you finish the run. Finally, whenever you enter Greece after clearing a run, you may be able to catch a sturgeon in the water, which you can trade to the Lounge chef for Titan Blood.
How to Use Titan Blood
The primary use of Titan Blood is upgrading your weapons and unlocking their Aspects. Upgrading the base Zagreus Aspect of a weapon only costs one Titan Blood a pop, but every other Aspect costs gradually more blood to upgrade. Hidden Aspects are slightly different, as their upgrades all cost 3 Titan Blood instead of scaling up. As for unlocking Aspects, it costs 1 Titan Blood to unlock a weapon’s second Aspect, 2 Titan Blood to unlock the third Aspect, and 3 Titan Blood to unlock the Hidden Aspect.
Titan Blood can also be used to unlock special House renovations from the House Contractor, as well as title upgrades from the Resource Director. These are just cosmetic, though, so for practical purposes, it might be better to hold off on those until your weapons are fully upgraded.