The equip cost of the new artifact in Core Set 2020 is quite high at eight mana, but you can combine it with Sigarda's Aid and equip it on turn two already.
This kind of approach fits decks like Bogles and Infect that can instantly kill their opponents. But there is also room for Colossus Hammer in other decks that run Puresteel Paladin or Kor Outfitter.
For example, if you manage to equip the Hammer and attack with Kor Duelist on turn two, then it's 22 points of damage, which is lethal.
There is definitely more than one way of breaking this card in Modern, and all of them look really exciting.