Looking for Chieftain Ballista build

Hello, I started as Burning Arrow Chieftain but after investing more than 20ex and reached 95, I don't feel good. I was expecting more from the build. Because of this, I swap to Ballista build. Tried both Burning Arrow and Explosive Arrow with Ballista Totem Support but they look really bad versus bosses. I am tanky but I don't deal damage. A fight with a Metamorph on T16 is at least 5 minutes. Killed the Minotaur for 15 minutes.

What would you suggest?