[Renojustin]

1) Using a battlefield enchantment that stays after the mage has retreated is a major shortlist issue and is not allowed. Using evocations, buffs, whatever, and retreating is just fine though.

2) Mists of Deception, even in conjunction with battlefield enchantments, is fine as well... but see 1). You cannot script the mage to retreat, nor have the Returning ritual cast on them, nor items with the same effect, if you use a battlefield enchantment. If there is a chance to kill them, and thus negate the enchantment, it's perfectly acceptable in my opinion.