Speed Boost Item

[Black117]

Like Honjunhu mentioned, there aren't many items which boosts Celesteela's speed stat immediate for one turn aside Adrenaline Orb, which boosts the speed of Celesteela by 50%. Even so, Celesteela needs to have a ton of speed investment to outspeed most of the format, though will to get outspeed by things like Timid Tapu Koko. Granted I've seen some Celesteela run Flame Charge to boost their speed by one stage every use, though despite the popularity isn't as effective.

unless the guy was running quick claw of course.