hehe good luck then as there are more of those dreadnoughts after you've got Hecatonchires. Still haven't beaten him though, got like pretty far when he blasted a rocked on my party leader (can only survive that attack with either a defender or a fully healed unit).
BTW mission 18 is in the mine, if you look around you can't miss it

Finally finished Chapter 11 today. Darn that Chapter takes long if your also set on doing the missions. I had to skip mission 27 though. I found the activation panel, but I couldn't figure out where the monster that I needed to defeated was. Will go back later to do that one again. Probably will do most missions again anyway (figured out on of the trophy's is "finish all missions with a 5 star")

Anyway the boss at the tower wasn't really hard. Already found a nice strategy during the first try, but he caught me off guard near the end. Didn't let that happen a second time of course

Then after a short walk through the village Oerba it was next to the old pope again. Got him down in the first try as well. Definitely turned out in a nice fight though.
Well after that it was over with Chapter 11 and time to head towards the final stages of the game. I must say the opening of Chapter 12 is worth watching
