You can find in apolymasks post here a great breakdown of everything posted above. The artifact can only be used for 5 rounds and then they are passed on.
Artifacts:

• Sortiarius Chest.
  Provides full upvote to your entry for 5 rounds from Apolymask

• Magic Dancing Shoes.
  Gives you advance information about upcoming challenges for 5 rounds but only if you're on the discord channel.

• Rare legendary artifact.
  Hidden Ladder. (This one given out numerous times for the best comments that we find that are left on any blog post associated with the IFC and can only be used once per person each season)
  A challenge will be given. If you solve it you will level up, if you fail you will lose as much exp as you would have gained.