Lightning Greaves helps creature-focused Commander decks put an important creature to work immediately while protecting it from targeted interaction. The equipment grants haste and shroud, and its zero-mana equip cost makes it easy to move between creatures during your main phase.
Haste is especially useful for creatures with tap abilities. Selvala, Heart of the Wilds can begin producing mana as soon as Greaves is attached, while Lathril, Blade of the Elves can use its tap ability without waiting through a full turn cycle if the rest of the activation is available. Attack-focused commanders also benefit from arriving with immediate combat potential.
Shroud stops all targeting, including your own. You cannot target a creature wearing Greaves with another equip ability, a beneficial spell, or a targeted counter-placement ability. Moving Greaves to another creature temporarily opens the original creature to those effects. Swiftfoot Boots offers a different balance: hexproof permits your own targeting, but its equip ability costs one mana.
Equipping normally requires your main phase and an empty stack, so the zero cost does not let you move Greaves at any moment. Opponents can also respond to an equip activation before the creature gains shroud. Sweepers and other effects that do not target remain effective against the equipped creature. Greaves works best when haste advances your plan and you can arrange your equipment and targeting sequence around its protection, rather than assuming it makes a commander untouchable.
