Power Swords

The Power Swords were weapons used by the Av-Matoran which could be used to effectively channel their elemental energies, as well as for melee combat. They came in many shapes and sizes.

Pieces
These pieces were also found in Garan, Click, Balta, Berix and Brutaka (both in gold), and Hydraxon.

Example Usage
In Comic 12: Realm of Fear, Tanma used his Power Sword to channel a burst of elemental Light energy at a Shadow Leech, incinerating it.