uber bosses hard to freeze as werewolf

the entire point of the werewolf is to freeze enemies, but as you get into the t3 bosses they become increasingly more difficult to freeze. with the main freezing ability costing nearly 100 mana it's become quite a struggle in the late game boss fights.

try to build up 40% freeze then Artic Howl

I'm using freezing mark so they freeze as soon as primed. Just fought Jamanra on a juiced map, he had around 30-40 million health. first freeze isn't bad, but after that it's like 1-2% a swing. assault is like 90 mana a pop. like i get it they don't want people just freezing bosses and killing them... but that is exactly how they built the werewolf. it's all designed around freeze then shred... these juiced bosses have a lot more health than the uber bosses.