The golden light emanating from the figure dimmed by a lot after having deflected the orange arrow, it clearly took a huge toll on the old man as he coughed some blood. He relied on the golden figure to act right now, it's practically impossible to fight along with it as it's not a Sovereign is possible to do.
Just activating the technique required Blood Essence and a high mastery of these arts, any person under the Sovereign Realm would certainly be unable to achieve what he did.
Arthur's control over the arrow was lost which is why it ended up exploding deep underground. He probably has at most one minute before he must leave the wolf's body, any more than that would be fatal to him and it will even cause him to lose the wolf's body, which is a valuable vessel.