This is a little worse than Hellkite Tyrant's similar ability, which only requires 20 artifacts, but Knuckles also costs two less mana and is always available in your command zone
Creatures (7) Planeswalkers (13) 2 Jace, Architect of Thought 2 Elspeth, Sun's Champion 3 Saheeli Rai 2 Teferi, Hero of Dominaria 2 Teferi, Time Raveler 2 Narset, Parter of Veils Lands (26) Spells (14) Ive seen a bunch of builds of this archetype already, some leaning on the energy shell whilst others try to play a slower, more interactive game as a Jeskai Control deck
Adelbert Steiner 2/1 lifelink for isn't the worst rate in the world
Now Tarkir is living in relative peace as many dragons live and fight alongside their human companions
For the bulk of a typical collection, this is the format that moves cards steadily
Considered very powerful, the wording on the card and its mana cost make it clear the designers are trying to not let shenanigans get too far out of hand