The void blade, that was how Luke named that attack, moved for several kilometers and ate everything on its path. The speed didn't decrease until it disappeared in the distance since it could devour everything, even the friction that the attack could have against things that could decrease its speed. It was one hell of an ability…
In any case, the other guys decided to give support to the dark armored woman from a distance since they didn't want to get caught in her crazy attacks, and they didn't have the confidence to dodge the Void Blade if they were too close to it. The spearman also could use Sonic Blade, and even though it couldn't be compared to the arrows of the archer or the lightning bolt of the mage, he could spam it and annoy the heck out of Luke.