The Halloween event was a complete joke.
This is how i would of done it based on the Shrine theme you had:
I would’ve Decorated a area in Kyovashad in a Halloween theme and put an NPC or Halloween statue that you interact with as a vendor, You get Halloween Tokens from Treasure Bags after killing Goblins from the Shrines, You can then trade the Tokens at said Vendor/Statue to get a Full Halloween themed Cosmetic set for each class. This would’ve given more incentive to click on shrines and made use of the Treasure bags better, All Shrines in the game should have been included not just the Dungeon ones and The Burning butcher needed to be way harder to kill and do way more damage - The Cosmetics would of been the Treat part and the Burning Butcher was the Meat part trying to kill you.
Unique 1 off Cosmetic sets that are themed for Halloween/Christmas etc… are actually worth doing a bit of grinding for, each year you make a different looking set with a different activity to keep people logging in and doing them