Etherblade

Magical weapon, common (Alien technology)

Manual of the Planes, page 31

The most common weapon of the ethergaunts is the etherblade. This weapon resembles a shorter-hafted glaive with a hollowed tube on top of the blade.
Glaive
When used as a melee weapon, th etherblade is a martial melee weapon that deals 1d10 slashing damage and has the two-handed property.
Ray of Force
The etherblade begins with 50 charges and making a Ray of Force attack with it expends 1 charge. When the etherblade runs out of charges, it can't be used to make Ray of Force attacks. When used as a ranged wapon, the etherblade is a martial ranged weapon that deals 1d6 force damage with a range of 30/120 feet and the two-handed property.

Alien Technology
Alien technology is complicated, obtuse, and nearly incomprehensible. A creature can make an intelligence check with tinker's tools as an action to attempt to understand how to operate alien technology. If a creature fails on this check by 10 or more, they may expend a charge from the item, activate or detonate the item (targeting themself), or (if they've repeatedly failed by 10 or more) even break the item.
The etherblade requires two successful intelligence checks to operate properly.

Item type

Weapon, Melee