To make a good deck, you want to focus on just a few strategies instead of all different cards and no real plan
With only one colored mana, he easily slots into three or more color decks
But what if we hid those in the 99, and just showed our opponents a casual chef that ramped until we could find one of the big beasties
Noctis Lucis Caelum You dont need to be rainbow for Kenrith, the Returned King to be good, as even just being WU makes this a great mana sink
The only thing you really have to look out for is cards like Terra, Magical Adept // Esper Terra, who flips back rather than being sacrificed
Lady Octopus, Inspired Inventor moves Jhoira, Ageless Innovator into mono-blue, but it builds up ingenuity counters extremely easily and can start to drop mid-to-expensive artifacts for free very early on