I imagine Temur will remain the best color combination, thanks to blues ease in achieving delirium, Snapcaster Mages synergy with [tippy title="Traverse the Ulvenwald" width="330" height="330"] [/tippy], and the immense relevance of a bullet Moon effect
You can have a good record with a Historic aggressive creature deck, or a mono-red burn deck in Timeless, because these decks dont rely that much on Timeless-only cards, but the competition will be fiercer, and Timeless is home to many broken combos as well
Buy Roaring Moon ex directly if that is the only target
Neither its attack nor the quality of its artwork can match the Fossil variant of the Pokemon, although it just has the edge when it comes to value despite being a little more recent
Alex P has given some great options, but I think this point is worth emphasizing: Play cards that are individually strong