Sentient eyes

Sentient eyes were created by the Ancient Builders to help them survive the Warden. They would be crafted by surrounding an ender eye in copper ingots, and they could be found in Ancient Cities and Strongholds. Sentient eyes can be thrown which create green fire, like throwable flint-and-steel. It can be enchanted with loyalty, mending, and unbreaking. It will have equal durability to flint-and-steel. It can be repaired using copper ingots. Sentient eyes could be used as flint-and-steel to start nether portals, ignite TNT, ect. Sentient eyes and the green flame are completely soundless.

Sentient eyes can be brewed to create a Potion of Seeing, which is like a potion of healing except it also clears the darkness effect and the blindness effect, and it gives the player night vision for 10 seconds.

They also have another purpose. You could build two portal frames with copper blocks similar to a nether portal. Using the sentient eye will link the eye to that portal, and using it on a second portal will link the two portals causing the eye to break. The oxidation level does not impact the portal. The portal color will be green-ish like oxidized copper instead of purple. Copper portals only function in the Overworld. The Warden is one of the only mobs which cannot use copper portals. This would be useful for long adventures, combat, and mining.