you can try this: Hidan halloween, Danzo and Hoichi but try to make him 4 stars.

as for main character you can be fire or lightning. try them both and see which one you like most both of them will buff your pos1 Hidan

ok my bad. you are trolling. i just saw where the bar is. you are not showing us all of your units. since you are having Hidan halloween you are also having Hashirama new year at least 3 stars because he is a free unit.

I would say fire main works best with secret jutsu users and ninjutsu oriented ninjas. check by base stats. Light main is best with sword and taijutsu damage dealers.