The system is several iterations away from the Numenera/Cypher ladder, though we haven’t touched a D20 for anything.
In a previous campaign we used a tiny stat (-1 to +2) + token spend system, where each player had 10 tokens to spend in an evening. If you spent all your tokens in one shot, you could achieve something truly worthy of myth (but then anything else would be, at best, “most people could accomplish this most of the time” results).
In the current run, it’s a low stat bonus (0 to +3) + D6 against a similar ladder. Magic is still a few tokens, held by the player and available for them to put towards whichever character. Characters are quickly noted as 3 points max across Mind-Body-Heart, and might have one or more colours of magic available. We might just put some colour dots on a piece of ephemera like a matchbook, paper clips on a NASA ISS mission patch, highlight some lines of poetry, or take a marker to a piece of grid paper.