I found a dungeon but , a dungeon guardian keeps killing me. My health lvl is 340 and my weapon is a light blood butcher. How can i explore the dungeon without it killing me.?
You need to kill Skeletron first (by talking to the old man above the dungeon at night). Otherwise the guardian spawns and insta-kills you.
The old man even tells you not to enter.
You have to kill Skeletron first. Talk to the old man. Don't fight till he says that you are powerful enough.