User blog comment:MagnoCosmos/Celestial Spirits Ranking/@comment-1153699-20150907164700/@comment-25121709-20150907223115

You didn't get my point. I just said that Lucy being able to open 3 gates means that she has enough MP so that Gamini can Copy useful mages. Aquarius also stated that opening 3 gates is a forbidden technique and a remarkable feat, so I think that it doesn't matter if it's Lucy or Makarov using Golden Keys, opening 3 gates would be equally exhaustive, since the power of the Spirit is directly proportional to the power of it's summoner.