At seeing his Flame's effectiveness Yukan knew that an obvious move was to let some of the forms from the treeline start to gather into a larger group before he struck again. So he'd ideally do that, but move forward after witnessing the bodies around him burn, so that he could get into a proper position to hit them again.

He took notice of his allies if he saw any from his current position. His nose twitched and he winced a bit. He did not enjoy the scent of burning flesh but it looekd like it was one which he would have to get used too. Since he hadn't really recieved orders to do otherwise and it didn't seem like anyone else needed his immediate support in Battle, Yukan just did what he generally did, and went in for another ring of fire when he was sure the enemies were far away enough from the forest that they wouldn't be burned, a fierey energy gathering over his body and shooting outward in a ring as he his flame blessed su yari lit ablaze while he aimmed it toward the central mass of enemies approaching. 

[b]Yukan Actions:[/b]
1. Wait for undead mass to get out of the tree line so he doesn't burn it down.
2 & 3. Move into position with a combination of Fast E and use an E grade version of Charging Great Transcending Thrust: