When he found the mark, Alros prepared for a lot of thing. He expected the mark to blow up, likely killing the Forest Drake and injuring him. He also expect it to unleash a powerful wave of energy and injure him.
There is also the chance that the mark will connect to him and try to parasitize him, absorbing his energy. Essentially, killing him by sucking him dry. Which will be an ironic way to go.
However, what he did not expect is for him to feel a part of him, likely his Soul but he just guessing, to be pulled somewhere. As it happened, his vision darkened.
-x-
When his vision returned, he find himself in a forest, which is not weird since he is already inside one. What is weird is that he could tell this is not a real forest.
He prove it by looking down and seeing himself in an illusory state.
"What is this place?" he muttered, walking around the forest to find a clue on how to get out.