For some reason, the ponies did not seem to be much comforted.  Forgath continued, undaunted.  "The work you can see here contains his essence - he's mostly made of magic in the first place - and prevents him from manifesting a more physical form.  Because pain is his nature and the nature of his magic, my array uses pain to keep him contained.  You can also bind using opposed forms, and it's often easier to do so, but it would be less useful as a source if I had.  As it is, I can draw off large portions of his mana and forge them into my magic; my flames especially benefit from them, and he regenerates quickly.  None of you should attempt anything like this yet; the workings are too complex, and this sort of creature is tricky to deal with."