­Returned Centaur + Swiftfoot Boots

Zombie centaurs are surprisingly tough. And they mill you. Because, um. Yeah, there's no real flavour match there.

And a simple equipment that grants haste. What a nice simple idea. Oh, and hexproof too, because screw-you, that's why.

So it's actually an underpriced whispersilk in disguise.

So, the components are: medium size creature, black, mill, hexproof, haste, artifact.

Humph.

Ok; how about making a french keyword mean something on later turns? That works. Turning damage into mill is usually not a huge problem - damage is usually more potent than mill. I think I remembered the name of the gizmo you have a horse turn to pump stuff? If not, it can just be another example of flavour nit quite working right.

Rarity: Globally affecting artifact; can't be common. Could be rare - it's niche enough. But I think it's a "Go build a mill deck" hint, so uncommon. assume the set its in has quite a bit of haste and other mill sources.

Cost... doesn't want to be too high; not to work alongside haste stuff. And if it's low, opponents get time to see it coming and figure out how to deal.

­Swiftfoot Boots is a reprint, and is in turn the updated version of Lightning Greaves from the very first set to include any Equipment. Both of them are just trying to say "speedy boots".

This is a pretty interesting idea. Amusingly it works as a sideboard card against a deck that has some haste creatures.