A bunch of recent Channel Fireball videos (LSV, Cheon, LSV again) show players exploiting Time Vault combos, where you untap the Vault with Voltaic Key or some similar effect to take infinite turns. That got me thinking that Time Vault seems like a pretty useless card from a competitive perspective if you're not using it in a combo.
Has there ever been a competitive deck that used Time Vault's manual untap ability, where you skip your turn to untap it? Or can anyone even think of a situation which could plausibly occur in competitive play where skipping your turn to untap Time Vault is a good (or at least defensible) strategic choice?