Red in particular in the format tends to be pushing the pace, especially with the Red/White go wide builds, and Red Black reckless aggro, though Red/Blues spell aggro is no slouch either
Some others are more flexible, like Kenrith, the Returned King, since their abilities don't point you in any particular direction
There are still hundreds of cards in Historic Horizons yet to be revealed, but I jokingly ask if we can assume Modern Horizons 2s now notorious monkey Ragavan, Nimble Pilferer wont be among them
One that has flown largely under the radar so far, however, is Weathered Runestone
This actually enables some infinite combos as well, such as combining the eminence cost reduction with Haakon, Stromgald Scourge + Morophon, the Boundless + Blades of Velis Vel to cast Blades for free infinite times to give our creatures infinite power -- but I'm getting ahead of myself
They are to remove loyalty counters from a card