Originally posted by Udrakan:

-the mist doesn't get cleared fast enough by the wisp when running forward, often leading to running blind in it

The wisp seems to be an actual separate entity. It will move ahead of you in the direction you are facing and moving, but the game (like all other games and virtually everything in this world) lacks precognition and cannot predict where you're going to go, so it will lag behind if you change directions a lot. Using the new sword to remove the mist has much smaller area but it's always focused on the player, so you can take your pick.

Overall, planning your actions more carefully will negate all of those problems, especially by the time you can craft the new cape, except bad dungeon loot RNG, which has been present in the game since the beginning. So long as you find at least one core and a fragment in dungeon, it's good.