Let This Grieving Soul Retire, Vol. 8 (manga)

All their blood, sweat, and tears...They ve spilled a bit more than the rest of you.The capital is in a clamor as word spreads about the arrival of a band of high-level hunters including Arnold Hail, the infamous Dragon Slayer known as the Crashing Lightning! Krai, of course, couldn t care less about anything other than the upcoming Zebrudian auction, but he ll be in trouble soon if he doesn t get his relics charged fast. Thankfully, Sitri has devised a top-secret training method that can both charge the relics and boost the whole party s mana reserves just in time for a pair of superhuman Noble Spirits who have a bone to pick with the Grievers!