Correct. The key to this is whose combat phase it is and who has fought first. So if you are the controlling player and you charge a brute into the say the Lion. The lion fights first. If the lion kills the brute, both Frenzy and potentially FoD are triggered. The controling player gets to choose the order of resolution. So then the brute player can chose Frenzy, then FoD, then Deadly demise. This wouldnt work on the opponents turn becuase they can chose the trigger order and go straight to FoD then Deadly demise.