Whatever historical truth lies behind the legend of St George, perhaps the story of St George and the dragon is based more on allegory than any distorted historical reality. What if the 'dragon' meant to be depicted in that story is not a 'natural' dragon at all, but rather a representation of something spiritual? Perhaps the 'dragon' represents one - or maybe even all - of the dark human passions that lurk within the soul? Perhaps slaying the dragon means conquering these passions?
What better way to represent the bad elements of humanity than as a dragon? And how else can the spiritual be represented than through analogous material images? But people who do not understand the spiritual may not interpret such images in a spiritual sense, but rather interpret them according to their natural meaning. Thus we have Satan represented as a man with horns and red skin and a serpent's tail - is that a real image of the 'spiritual' Satan? I very much doubt it, but it is a 'worldly' or 'natural' representation.
So what then is Satan, and what are devils? How can these be depicted visually? Can the spiritual be depicted visually in a way that is really representative? Perhaps at best a picture can only allude vaguely to a true spiritual concept, which can only be really understood in its spiritual sense. So devils and Satan represent the wickedness, which is a spirit, as love is spirit. Love is perhaps a good example. We cannot really depict love in a natural, really representative, way, but only through analogous pictures which hint at its true spiritual meaning: hearts, kisses etc. So why then do people have trouble understanding - and accepting - that if there there are good spirital forces - like love - then there can also be bad ones? Many people do not associate the spirit of love with a particular personality (although love is in essence God's spirit, and God of course has a personal 'I') so why do people feel it necessary to associate evil with a personality? Evil spirits may be just that - spirits, not actual beings. However, people infected with these evil spirits may well become 'devils' and of course will have a personality, but that is their individual personality, and they could hardly lay claim to be the very source of evil themselves, at most they have just become a 'part' of it, or perhaps a better word is a 'carrier' just as somene might become a 'carrier' of a disease, infecting others as they go.
So maybe the concept of a 'personal' devil or Satan, is not really a useful one. Perhaps a better way to think of evil is like disease, impersonal, spreading from one person to another, or arising spontaneously in an individual if the incubating conditions are right. So how might such evil arise? Well like a disease it might be hereditary, i.e inherited from one's parents ('the sins of the fathers are visited on the sons'), or it might arise through 'unsanitary' conditions (a spoilt upbringing, for example, may feed the illness of selfishness. Insecurity and lack of love may cause anxiety - a true curse) or it might be 'passed-on' from one person to another (i.e be wary of whom you associate with - "Bad company ruins good morals" - 1 Corinthians, 15:33.). Thus, like St George, we all must fight our inner dragons (i.e the bad spirits/inclinations that infect the human flesh and soul) and think not of natural things when considering devils and evils, but rather spiritual things, which are only crudely represented by analogies from the physical/natural world.