He changed his pants

After battling for over four hours, Mike finally saw the boss's health bar hit rock bottom. 

"Wind Fury!" 

"Void Tremor!" 

Both attacks landed almost simultaneously, wiping out the last of the ice dragon's health. 

Boom— 

In its death throes, the ice bone dragon smashed the surrounding stone walls, causing the entire cave to shake violently! 

Mike leaped up, dodging all the falling rocks and putting distance between himself and the ice bone dragon. 

He thought to himself, "Since it can have a dual form, who knows if there isn't a third form?"

[Yes, there is.]

Before Mike, the ice bone dragon began to change dramatically. The two large eye sockets on its skull, previously glowing with dim soul fires, now blazed with green flames that drifted out, emitting an evil aura and conveying a sense of terror. 

Anger, destruction...

Mike raised an eyebrow, watching the scene unfold, as if he had figured something out.