A teleportation spell was one of the hardest spells to do as it required a lot of time, mana, and knowledge to be able to use. Now that was just a normal teleportation spell, but a forced teleportation spell was three times harder to do. A normal teleportation spell was easy to break free from, as long as you resist a little with your mana, you'll be able to stop from teleporting. On the other hand, a forced teleportation spell disrupts one's mana flow for a short period of time making them unable to resist the spell. Still to use such a spell would require a ton of time and it's not a spell that could be used in a fight without preparations, so the spell was mostly used as a trap.
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