User blog comment:Linathan/Unit Spotlight: Mayhem Empress Luly/@comment-27691408-20160424053456/@comment-24570336-20160424103028

Probably cause Beiorg's Armor is very sphere efficient, since it gives 5% less all stats than Bourn Jewel but also offers healing per turn and from damage taken. That healing can add up into bonus HP eventually that beats Bourn Jewel.