Recommended Stickers:
- Hair Dryer Thing Sticker (CRUCIAL)
- Fire Flower stickers (Shiny/Flashy if possible)
- Shiny Hammer / Flashy Hammer stickers
- Super Mushroom stickers
- Life Shroom
Strategy:
Mizzter Blizzard is a giant snowman who can freeze Mario, preventing him from using stickers. To defeat him, you need to melt him. The Hair Dryer Thing Sticker is your best weapon. Using it will deal massive damage and remove his icy defenses, making him vulnerable.
If you don't have the Hair Dryer, Fire Flower stickers are your next best option, though they are less powerful. When Mizzter Blizzard is not frozen, use your strongest Hammer stickers. Be wary of his ice attacks, which can inflict the 'Frozen' status. If Mario gets frozen, you'll lose a turn. Keep your HP high, and use the Hair Dryer whenever possible to chip away at his health. This fight can be a war of attrition if you don't have the right Thing Sticker.