What's you're recomment for portal barb?
dream helm on merc to proc death triggers, rest is irrelevant, so you might as well use insight for the mana regen while teleporting around once everything is dead
problem is armor is also mostly irrelevant since nothing will be alive to hit / leech from
I guess you could skip holding a sunder on yourself by using dream helm + dragon armor, so only a fire+light immune monster wouldn't die instantly, then you can just let your merc hit it or leap once and it will die anyway
that's probably the ideal setup, so you could stack more %mf charms or open more inventory space, its not like sunder -resists matter if nothing is alive to damage you