If you guys like time spells, here's another suggestion:
Looper trap Cast on a character. The next attack on this character will trigger a time loop: the attacker will be repeating the same attack again and again, at the beginning of each turn, from his initial position, without being able to perform any other action, until someone gets him out of the loop by attacking him.
Visually I envision a semi-transparent image of the enchanted character flickering at the initial position (as he may move while the attacker is trapped) at the instant the attack is repeated.
Actually if the attack had several targets, all of them flicker again when it is repeated.
And if the looping attacker gets moved (by a gravity spell for instance), his flickering figure will still occupy his initial position until he's returned to that initial position at the beginning of his next turn, or the loop is broken.
For game mechanics:
Anybody in range of the repeated attacks will get hit. But range doesn't get adjusted for new targets (since the attack is simply repeated). For instance, a lightning bolt having ranged all cells on a line will damage new characters stopping on that line, on any of the cells initially included. But a meteor shower having hit visible enemies (say for instance 3) will not harm a fourth one becoming visible during the loop. Only the 3 initial positions will be hit by meteors. A melee or range attack will target the initial position(s).
If the attack is the result of a spell and enough mana is available, mana is spent and the spell is repeated with the above range considerations. If not enough mana is available the visual effects of the spell do take place, but in semi-transparent flickering fashion, and no effects are taking place.
When trapped in the loop, counterattack is disabled.
If a character stops at the initial position of a trapped attacker (despite his flickering image), he will be knocked back when the trapped attacker is returned to his initial location.
Intended game play:
With this trap one can take out the vicious range attacker, backstabber, or range damage spell caster: get him into a loop, then move freely your pieces around him to exact revenge, all units at the same time if possible.
Of course the opponent may try to avoid this by attacking the trapped character himself. But by doing so he also deals damage, which means that revenge is still exacted to some extent, even if indirectly.