Does Ironbark’s thrid trait actually do anything? He seems to be doing the same amount of damage to Towers as before I unlocked his third trait (Siegebreaker).
A multiplier is listed in the description of his attack but another (similar) multiplier is listed on the third trait. If you do not get an EXTRA multiplier from the third trait, why would anyone ever unlock it?
One of the towers reduces skull damage by 75% (or so) The blue and brown one, forget its name, otherwise he hits pretty hard with the 3rd trait 
Double check and make sure it’s not modifying the skull attack instead of the normal attack. I made that mistake 3 weeks ago. It’s easy to confuse the two types of attacks.
His spell always does 3-5x damage against towers, but the third trait applies to skull damage (as opposed to spell damage). Mine seems to be doing what it it supposed to be doing, but I didn’t try it before traiting it.
Thank you for the responses.
I did make a mistake. I see now that the third trait applies to skull damage. Thank you for pointing this out to me. I will read the traits more carefully in the future. 
Also, don’t forget that one of the Towers Stuns your troops. Therefore your traits can be disabled from time to time.
The Bastion Tower reduced skull damage by 75% so it would look like a normal hit. 
My complaint is what is the point of putting this and untangle on a boss killer when all of the towers are immune to status effects, mana drain, transform, and lethal damage…
Just a point of clarification: Ironbark is a siege breaker, not a boss killer. He’s not powered-up against Zuul’Goth.