ooh sorry i must have missed the flame angel... yeah the best way to add fish is by adding the nice ones first. seing how your flame has been in there nine months i dont have a clue on what you could add that is not more aggresive than the flame its self. you could try this though, mess around with the aquascaping a bit right before you add the new guy. this should get everyone back to neutral... teritory wise. or even better if you have a QT, use that to put the flame in for a couple days or until your new fish becomes used to your tank then put the flame back in (after you reaquascape of coarse).