The reason for this is mainly that since the printing of Ragavan, Nimble Pilferer, Dragons Rage Channeler and Murktide Regent the tempo archetype reinvented itself in being primarily blue-red and making Deaths Shadow not a necessary creature for tempo shells anymore
It has ten distinct color pairs, each with its own themea step away from Core Set 2020s mostly loose tricolor themes
A cheaper but a bit less good Chaos Warp
The floor on these in a deck triggering multiple upkeeps is still very high, especially when youre playing one, become the monarch, and then get your combat damage trigger from Obeka
But if you have a base-set card in your card collection, there are a few visual indicators of its worth
He does sit high on the curve for Artifact decks, but the potential to keep fueling the fire may be worth finding a spot for him