Single Comment

There is nothing wrong with the mechanism of summoning itself. What wrecks things is that you automatically get the Demon back in hand when it gets captured. That effectively makes it an 'iron piece'. Giving the opponent two moves, knowing that he has those, is too costly, though. In the opening you might get away with it, but in a typical middle-game position the opponent would use those to make a hit-and-run capture.

Furthermore, summoning a Demon for free seems too easy; in horror stories one typically has to make some sacrifice as part of a summoning ritual. Using this concept the following might work: to summon a Demon, the Mage should first capture a friendly piece. That will then 'activate' him for summoning a Demon in the next turn. But depending on what the opponent does in his turn, you might pass on the opportunity to summon, and do something else. That would waste the opportunity to summon, and you would only regain it by capturing another friendly piece.