"Gil, fire arrow!" The moment that Walker called out, Gil was already in motion before Walker had even called up the fire mana to improve the fire arrow that Gil was letting fly.
The added fire mana massively increased the flames swirling around the fire arrow. So much so that the arrow itself lost form. The only thing holding it together were the fire runes originally carved on the arrow to make it attract even more fire mana. This was the base that allowed Walker's mana to gather there and enhance the effects.
The result was a much greater fire arrow made of pure fire heading right for another of the rage filled howler wolves. When it impacted, it burst in to flames which forced the other howler wolves back. They might not have felt the pain of burns from the attack that spilled out on to them, but they still reacted to the sudden burst of fire that made them blind for a second. It was a natural instinct.
