I feel nin/ really needs a AOE heal and heavy debuffs or buffs to last so the best option there is /dark , but sense you don't want to play another /dark . I would say necro/storm would be you're best bet . With the self healing and crazy tohit debuffs from the lich stacking with hurricane .
The nin/ end of things with storm would be nice but not as tough , (Wish they would buff nin/ def a little >_< ) the best bet for them with out playing over something you have done would go to nin/therm . forged-smoke flash-oni would be fun
I mite have to give nin/FF go . power boost and FF will cap there def unless they changed power boost sense last time i looked . Hmm just did the math and add the def pet IO genin would hit 45.83 with out power boosting bubs , at level 50 that is .
(Edit i wouldn't go with nin/pain sense it's lacking real buff a small res buff with mostly heals and regen mix that with melee pets and your going to be spamming heals all day you will with therm as well but not as much .
lol almost 4 years and only 9 post O_o game is to fun to spend to much time here

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Well theres my take on things hope it helps