He had to thank those three men for their brazen assault upon the village, without them, he doubted that he would have gotten even the smallest of chances to intrude upon the castle, but Griar had to make a swift decision, he either had to simply run in and hope for the best, or attempt to use a spell to make a more discreet entry, with the high reward of not having to fight whatever amount of guards were inside, or the high risk of being discovered without the possibility to use another spell for a little while, which might just spell death for him.
However, he greatly doubted that just running in would not get him killed either, if even one saw him, which would definitely happen if he simply ran, they would alert all of the others and getting away from them in the unknown layout of the castle would be next to impossible, so Griar made his decision and employed a spell he was not that confident in.