Forum:Cronus, World Hydra

Hi guys, I have question about Cronus Monster. Some people have Attack buton cost 1 stamina and Power Attack buton cost 5 stamina and some people have 2 Power Attack buttons cost 10 or 20 stamina. Do you know when I can get them 10 and 20 stamina attack buttons? What I need - bigger army, higher level or whatever? I'm level 212 with 148 army members and my stamina is 165 points. If someone knows I'll be glad for answer. Thank you. Grga