Ring of Fire Arts: Krievol received it from Yusuke; Normally when he imbued fire to his spear there would be a wavering flame that seemed to twine and blaze around the spear, but with the ring the flame seem to be from the spear itself like it was focusing on the spear, thus appearing like a flaming spear instead of a spear wearing flames.
Zeshald: For king Esvobus, a fire art user of great strength, to show favoritism to Zeshald made his faithful retainers, including Kreivol, harbor displeasure towards Zeshald.