How do multiple uses of the same spell or ability used by different characters on the same target interact?
Specifically, this came up in the last session with Control Animal. Some animals were being controlled by this critter power (is that what it is?). The mage in the group summoned some spirits, who owed him tasks. One of the tasks he gave to one of his spirits was to control any hostile animals who made their way into the encampment, and cause them to attack each other.
The problem is that the animals were already being controlled by Control Animals, which was used by another mage or something, AND they were being "Influenced" as well.
So the question is, which "casting" wins? Does the FIRST casting take TOTAL control, and another caster can only gain control after the first casting has "worn off?" Or does the MOST RECENT casting supersede the first? Or is there a kind-of mage battle to determine who gets control?
Further, what about different spells and effects with similar... effects? Like Influence and Control Animal? How do these interact?