Nice on the 3 rares! I pulled my 3rd rare this morning myself, trying to see if I can get Chojuro to work now, but still, I'm sorta jealous that you got that guy for the first rare.
I've been testing them out, and in arena, they're somewhat good. I main water so, can't get the full force of the duo, but They can make a combo if used right, but I wouldn't call them a great duo, but they're good.