I've got a duelist, shadow, ranger, maruder, or witch to choose from but I want an extremely powerful fast clearspeed boss killing machine. Suggestions?

I've got gear like saviour and other high end items to gear with, I'm getting bored of my CoC dual cospri ice nova assassin.. I've tried a few other builds but can't seem to get them to peak performance

I like vaal double strike, can go gladiator or berserker, melts bosses, mathil has a vid of it too,

herald stack
got another week to abuse it

Thanks guys

After that................... Totem Minnion ABUSE !!! wooooohoooo !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!