Hm... we're getting into YMMV territory here, but I never saw Gryffindors as having a hero complex, really. In my opinion, Gryffindor and Slytherin are somewhat alike in that they both have a tendency to be competetive and proud, but their methods of reaching their goals differ. I'd say that to me, out of the MKR girls, Fuu seems the closest to Slytherin (although, admittedly, Umi would be second). Umi kind of has aspects of all Houses - barring Ravenclaw, possibly - but I'd personally list her as a Gryffindor.