Had lots of fish, from auratus (nasty little devil) to red devils to jags, but I have never kept a fish nastier than a Labeo chrysophekadion. This guy is by far the meanest fish Ive ever had, loves to throw his weight and size around, gets consiterably nastier when either hungery or around feeding time. So far Ive yet to keep a cichlid or any other fish who can hold its own against this beast. I suppose because of its size and teeth, a dovii could probably maybe "take him", but teeth aside I dont think Ive ever even come across a dovii with the desire to hurt other fish like this guy.
Profile:
http://www.aquariacentral.com/species/db.cgi?db=fresh&uid=default&ID=0538&view_records=1
Profile:
http://www.aquariacentral.com/species/db.cgi?db=fresh&uid=default&ID=0538&view_records=1