He told Ren that his OverSoul is the fastest of all the Guardian Spirits, so he stabbed Ren at his back with his special ability Dancing Insect.
Then Nichrome followed with his another technique, Dancing Insect then Dreaming Needle which can poison the target.
Because of this attack Ren releases his other OverSoul Bushin Fish Fin and Nichrome counter it with his combine attack of his Oversoul.
Then the battle was finished ending Nichrome defeated and Ren almost died because of the poison. But with the help of Fauz the poison was taken out from his body.