Berg Strider

Blue tempo has always folded a partial removal effect onto a body: the Man-o'-War school gave you a bounce the moment the creature landed, unconditionally. This 4/4 belongs to that lineage but gates its best mode behind a deckbuilding cost. The entry trigger taps down an artifact or a creature no matter how the spell was paid for, so the card contributes even in a manabase that ignores snow entirely. Feed it mana from a snow source, though, and the tapped permanent stays down through its controller's following untap step, converting a single-turn stall into a two-turn soft-lock on one permanent. That conditional carries the whole design: it rewards a manabase built around snow-covered lands without stranding players who skip the theme, since the tap resolves either way. Because the payoff rides an enters trigger rather than an activated ability, the snow bonus fires once per cast, buying a clean two-turn window rather than a repeatable lock. It reads as curve filler and behaves like a build-around: forgettable when snow is an afterthought, quietly oppressive when every land is tuned to trigger the upgrade.