**EDIT**
Well I never killed an orochimaru yet, im still semi-new to the game and im lvl 4.
Right now there is only 2 specialties, Taijutsu, and Genjutsu.
Here are my suggestions;
Puppetry
Some Skills; Puppet Replacement Technique, Poison Fog, Kuroari Grapple, Sanshouo Defence, Blind Spot Destroyer (Dokugiri Zuyoku, Baribari Shikaku Renpatsu), Black Secret Technique Machine One Shot, Black Secret Technique Machine Two Shot.
Shadow Manipulation
Some Skills; Shadow Manipulation, Shadow Strangle etc.
Weaponry -(Can have characteristics similar to ten-ten, demon brothers, the ressurected guy in ep 219 who made the 'ultimate weapon')
Some Skills; Twin Rising Dragons, Throw Kunai, Throw Shuriken, Throw Wind Demon, Unleash Seimei's Ultimate Weapon (increases str)
Air Manipulation - (similar to the sound ninja who had air blasters in his hand)
Some Skills; Air Slicing Blast (Zankuuha), Ultimate Air Slicing Blast (Zankuu kyokuha)
Clay Mastery (Exactly as Deidaras skills, where he makes clay birds that explodes and that big one that was similar to an atomic bomb where he tryed to blow up the sand village)
Some Skills; Exploding Clay (起爆粘土, Kibaku Nendo?), Suicide Bombing Clone (自爆分身, Jibaku Bunshin?), Clay Bird Explosive, C3 (The biggest clay sort of like an atom bomb)
Each specialty can have 1 ultimate technique just as taijutsu has Konoha Senpu, Puppetry can have a fusion with the puppet and the user similar to what Sasori does causing more damage, Shadow Manupulation can have Shadow Strangle or w/e its called, well you get my drift.
BTW since im kinda noob to the game, where the hell do I buy kunais and explosive tags, like the ones we start off with when we make an account.