Some content in this article is derived from information featured in The X-Adults: Endgame: The Latest Threat, and, as such, spoilers will be present.
The sword was designed crudely. The design was an ancient one, dating back hundreds of years to medieval times (of course, the sword resembling the sword and the energizer in one, and not the sword itself). It was built with six cracked series of wooden energizers (usually ten are required, and twelve are recommended). The energizers could barely contain the energy shell’s power. As a result of the broken energizers, the sword required vents on either side to divert the excess heat, necessitating its unusually wide hilt. It also gave the energy shell an unstable and fiery appearance. 
- The X-Adults: Endgame: The Latest Threat (first appearance)