The Angel Of Death
"I do not wish to fight such lowly soul like you. If you want the orb, be deserving of the orb. It's not like I can give it to you, work for it."
Okay that's it. It looks to Nisemono that the guardian doesn't just want him to have the orb. If the guardian wants him to work for it, then he'll fight for it. One thing that the Angel Keisuke gave Nisemono was the power called Phoenix, a fire bird that can attack its enemy, giving a fatal burn.
"Phoenix," Nisemono calls and his power appeared. Like some kind of spear, he throws it at the guardian who was now sitting calmly on the branch. As soon as the fire approached, Pika just snapped his finger and like a bubble Nisemono's attack disappeared.