The ice wand is one of the new artifacts. It stuns mobs, has a 20 second cool down and does around 12,000-13,000 damage when it’s level 113.
Once unlocked via completing Frosted FJords or Lone Fortress,simply go on a very low difficulty get 5+ enemies stacked on you and activate it.
I unlocked the achievement on ???( cow level) just rounded up a group on default IV and activated it but any level dlc or not should work