Below is a break down of Mana Crystal.
Zone Exclusive
Many conjurations have a trait called Zone Exclusive. Each zone can only have one Zone Exclusive conjuration at a time (even if those conjurations have different names). You may not cast such a spell that targets a zone that already has a Zone Exclusive conjuration in it.
Flame Immunity
This object is immune to all attacks, damage, conditions, and effects of the specified damage type, including critical damage and direct damage. Cannot be targeted or affected by spells of the specified type.
Controller gains Channeling +1.
Modifies a creature’s Channeling attribute by +1. Modifies only existing Channeling, it has no effect an object without a Channeling attribute.
Nothing in the first set is based off controlling a zone. I hope that helps