First time in hardmode, pre-hardmode boss, and I got to space for some reason and get one shotted by an arch wyvern.
I respawn, attempt to get back up to the floating island I was on when I died and get killed by another arch wyvern.
At that point I gave up and just crafted stuff in my base, prepping to go mining, when I get one shotted by the same arch wyvern.
Turns out that wyverns on the 3ds edition don't despawn after they kill you, they fly to the top of the world and go out of bounds, but don't despawn, they come back to kill you again. Sure if you are prepared and get lucky by getting mostly normal wyverns them not despawning and making you lose progress is awesome, but I was nowhere near prepared, my best gear being a Night's edge and Molten armor.
I got killed so many times before I even was able to dodge the thing, and died even more trying to kill it...