Trying to figure out how low I can get my lightning resist with doryanis prototype using double self curse ele weakness and conductivity, dual ventor rings, multiple threads of hope

What's the most reliable setup in shackles of the wretched to dual curse myself for nit onky mapping but bosses as well.

Herald of thunder would be ideal considering ill be running it but the problem is that it's ticking is non existent for bosses unless I kill a shocked enemy (writhing jar < which i dont want to waste a slot)

Any ideas?