Taking into account Rex's little rant, you have forgotten that how long dragons are grown before fully mature. Once done, they are extreme tankards, and can devour some of these things without problem. Flaws, if any, would be the fact you could contradict their element. Demons on the other hand, are just cultic creatures, like Rex said, summoned, and usually were slaughtered whenever a mob accused their summoner of occultic deeds, thus killing them. HOwever, they would have aspects of necromancy and pyromancy, and if things like earth, wind, or ice demons, those qualities possible. However, dragons were always feared because simply their fearsome look. If anyone is stupid/brave enough to take on one of these, it is usually a fairy tale where the hero ALWAYS wins , gets a princess, and lives happily ever after to die of a heart attack. Well in dragons, most people would think some massive creature, huge wings, that kind of stuff. I call on the proof of MTG cards to show any strengths/weaknesses http://mi.wizards.com/global/images/magic/general/dragon_tyrant.jpghttp://www.wizards.com/global/images/magic/onslaught/grinning_demon.jpg