This predicament has probably happened to you. You entered Stormveil Castle, took the side path, and went through the castle only to get trapped in a room with a Banished Knight in some sort of Patches-style trick. Of course, it might not have been extremely obvious who actually performed this trick and trapped you in a room only to get mauled to death by a knight. If you want this problem to stop, you gotta cut it off at the source. Here is how you can avoid getting trapped in the room with the Banished Knight in Stormveil Castle in Elden Ring.
Of course, the most obvious way to avoid getting trapped in the room is to simply have Gostoc tell his friends to open the gate. You can then go straight through, while avoiding a barrage of arrows from multiple ballistas, to reach the other end of the castle. Of course, this doesn’t sound like the best idea so you will probably want to opt-out of taking the main gate and stick to the side path instead, just like Gostoc told you to. If you take the side path and have a long enough weapon like a spear, you can attack the wall next to the door to lure the knight out before going inside. This can also prevent you from becoming his practice dummy.
Gostoc is a rather peculiar NPC. He acts strangely like Patches and is the one responsible for locking you in the room that you most likely died in while progressing through the castle. While he becomes a merchant shortly after performing this little trick, that doesn’t excuse his actions. If you choose to kill Gostoc before entering the room, you can avoid getting locked inside. Unfortunately, that doesn’t make the knight go away, but at least you can easily escape.
