Gostoc

Gostoc is the gatekeeper at the entrance to Stormveil Castle in.

He's found in a room just to the side of the castle. While he may seem a bit suspicious, overall he doesn't actually cause harm as he'll suggest taking a more discreet way in rather than via the front gates, warning you it's heavily guarded if you try the latter. However, if you choose you want to go through the gates anyways, he'll respect this and even open it for you. That said, this way is true to his word, with enemies and ballistas throughout this area.