Three drops like Gaelicat and Tidus, Blitzball Star can rack up damage fast while evading or neutralizing blockers, and Slash of Light will be at its most effective
They can also be disruptive or staxy, leaning heavily on the white element, or focus on synergizing with fliers or flicker effects, which is a little bluer
Yes, you lose some life every turn, but The One Ring is also indestructible, making it extremely difficult for your opponents to interact with, and you really should have some bounce spells to maximise the potential of The One Ring (and to not lose too much life)
At the beginning of your end step, create X 1/1 black Fungus creature tokens with "This creature can't block," where X is the number of times you descended this turn