An Aiur zealot wielding a solarite reaper
Solarite reapers are an ancient protoss poleaxe weapon designed during the age of the Protoss Empire. Many of these weapons were sealed away with legions of Aiur zealots in the arkships beneath Aiur. During the End War, these zealots and their weapons were released aboard the Spear of Adun. Aiur zealots were able to spin in place with the solarite reaper, causing a whirlwind attack that hit all enemies around them.
Trivia
Solarite reapers are likely a reference to the arcanite reaper weapon from World of Warcraft, which has a similar design.
References
Blizzard Entertainment. StarCraft II: Legacy of the Void. (Activision Blizzard). PC. War Council interface (in English). 2013-03-12.