It's a solid build, a little shaky in the beginning. They way you build your skills is kind of weird. Mainly because Rammus relies a lot on the defensive ball curl to block most stuff and mainly magic damage. Powerball is just used to catch people and stop them real quick, so in my opinion that would be the last thing to get. I like the warmogs armor buffs your health to a ton I think I had about 4108 hp in the end. I would just get warmogs last. I play a build where you get ninja tabi, sunfire, thornmail, sunfire, atama's, then guardian angel. But I might switch out guardian angel for warmogs now. Not the best build but still solid works very well late game, not so much early game and I think that's because you're getting warmogs early and that is a huge gold suck so it just takes a while to build up your defense while you're trying to get that.