Rarity reflects design uniqueness more than raw strength.
Given how T'Challa works, you're not going to be short of colorless mana to cast artifacts, yet of the 24 artifacts in this deck, a quarter of them are mana generators
When this was first announced, a Reddit post (which I encourage you reading before continuing) went fairly viral claiming that a user with a 55% win rate would take about 3 hours of grinding per day for a month for a user to reach Mythic
Rafiki, Mysterious Sage Hit your opponent before they have a chance to react The Lion Kings wise mandrill takes a surprising preference for brawn over brains in Lorcana, striking your opponents with solid attack power before they can do much about it
Avacyn, Angel of Hope Avacyn, Angel of Hope represents top-tier protection, which puts her firmly on any shortlist of the best Angel commanders in MTG
Idea stolen from User:JiFish's creation of Image:Jimbo mtg Photo credit goes to Kira Wales (Image:Jimbo Wales in France , also released under the GFDL), in case you can't make it out on the bottom