How the HEEEEEL do you use Ulthan

I absolutely got wrecked by a ulthan like no other. No matter where u was. He would show up. And then I’m just stunned. Stunned. Can’t use my skills. Nothing.

How do you use him. Do you pick one character to harass?

What combo do you use? I’m assuming it’s something like.

Skill 2 into a wall.

Skill 1.

Then rush attack for a stun.

Skill 1 again second part.

Then skill three.

Rush attack for second stun.

Then what?

When do you use ULT. What cards? What’s his job on boss fights?

Everything I need to know.