Aeolian Dark landed with CS2’s Fourth Season Skins on 21 January 2026, inside The Achroma Collection. It’s a weapon-category skin—hydrographic finish, Common rarity, 0.0–0.65 float cap. Valve is credited as designer; this is straight from the update, not a standalone Workshop drop story.

Think of it as Achroma’s gray-scale anchor: the pitch isn’t saturation, it’s abstract knot repetition and the line “Go with the wind” (随风而行)—cool, light, slightly haunted energy that matches the name’s wind-and-shadow vibe.

What you’re actually buying

• Finish type: Hydrographic—pattern stretches over curves; thumbnails lie more than in-game inspect does.
• Pattern read: Gray knots and base fight for contrast; float drives the whole mood.
• Set role: When you’re building an Achroma loadout, this one doesn’t clash with higher-tier skins in the same collection—it holds the gray lane open.

Wear & inspect checklist

| Float zone | What changes on the knots |
|------------|---------------------------|
| Low (near 0.0) | Cleaner gray steps, sharper knot structure, easier to “read” the weave |
| Mid | Balanced fade; good if you want used-but-not-muddy |
| High (toward 0.65) | More weathering and haze; knots blur into the base—moody, not crisp |

Before checkout: spin in-game inspect under different lighting. Pay extra attention where handguard, receiver, and mag meet—hydrographics often show seams there; you want the knot flow to feel continuous, not chopped.

Where it drops & how to hunt it

Source is The Achroma Collection; exact drop or exchange rules follow whatever the game shows that season. Off-client, search by display name or Achroma keywords on Steam Community Market or C5GAME, then match listed float to what you saw in inspect.

Internal ref: hye_abstract_knot_m4. English listings often say M4A4 | Aeolian Dark—same skin as the CN 风蚀幽冥 naming in official materials.

Shopping verdict

Worth picking up if: you want a cheap Achroma brick for a gray-themed inventory, you like texture over neon, or you need a neutral M4 that won’t fight flashier collection mates.

Skip or go budget if: you only buy skins for loud color or FN-only flex—at high float the knot story gets soft fast, and Common means no rarity chase.

Sweet spot: a float that keeps knot edges readable without paying for vanity; verify on inspect, not screenshot.

Editor’s aside

Hydrographic grays are sneaky: they look “plain” in a grid of thumbnails, then open up when the knot rhythm wraps the mag. I’d rather overpay slightly for clean transitions at the three body breaks than save two bucks on a float that turns the weave into smoke. For set builders, treat Aeolian Dark like concrete under the furniture—boring until everything else sits on it and suddenly the whole Achroma shelf looks intentional.