I got 3 kenyii/lombardoi (1 male 2 female) and I would have to say they go extremely hard! At feeding time I hand feed them, sometimes they even latch onto my finger until they are about 10 cm out of the water. They are extremely aggressive and the females eventuallly ended up killing the larger male. I recommend putting them in with fish at least 1.5 times their size, unless you want to see the other fish get mauled. They ripped half the bottom jaw of my 20 cm oscar, who repetively tries to eat them, and mauled my 20 cm catfish so all that was left was a head with no eyes. A word of warning: don't let this fish get hungry!
Pseudotropheus lombardoi are not a pairing fish, it is far more successful if you have them with 2 or more females. All lombardoi start off blue (females remain blue while the males turn yellow when they get to about 3-4 cm). Of course they are aggressive, they are one of the most aggressive fish from lake Malawi, all Mbunas are aggressive. They are a playful fish, although I theorise that it is more and act of assertion when they attack your hands, simply them trying to prove who is stronger. While it is a lot of fun to play with our fish, you must also remember that frequent contact is detrimental to their health and that putting things like plastic balls or any thing artificial in the tank can be harmful as it can stress them.
I have a male kennyi with 4 demasoni, 2 frontosa, 4 figure eight puffers, 2 yellow labs and 2 plecos. He is by far the most aggressive fish I've had to date. He chases the puffers as if they were passive little fish, even though they mauled apart a female kennyi I had before. Extremely territorial...he claims my 300 L for himself! If your looking for a community fish, this is not it!
These pages have enough comments to give the reader a basic idea on the topic. Further comments are still very welcome (through the site's contact form) as long as they provide new and/or advanced information not yet discussed in the existing ones.