1. the sage of six paths, uchiha madara [Second Rikudo], Nagato [Third Rikudo] and Uchiha Obito.

2. His first heart was destroyed by kakashi, His second heart was destroyed by hidan, Two more hearts were destroyed by Naruto's wind style rasen shuriken, His last heart was destroyed by kakashi

3. Two pots with 3 flower each = 6