I acquired a 14/13/12 shadow Beldum from Sierra two months ago.
Only twice have I ever maxed out a Pokemon below 96%. If purified, it would be 98%, but it would have higher DPS (not sure about TDO) as a shadow. Since Sierra’s lineup has changed, I will not get a higher-IV one for a long-time.
Whether I TM away Frustration in the upcoming event or purify it, for it to get Meteor Mash, I must either wait until December or use my only remaining Elite CTM (I already used one on my perfect Mewtwo). My other candidates for the Elite CTM are a perfect Groudon, a perfect Venusaur, a 98% Rhyperior and a 98% Blaziken.
My current team for Kyurem comprises (all maxed out and with CD moves where applicable) one Rampardos, three Rhyperiors, two (regular) Metagrosses, one Conkeldurr, one Dialga, one Reshiram, five Machamps and two (both purified) Tyranitars.
Stardust is not a problem (sitting on 3M+) and neither is Beldum candy (earned 1000+ from CDs and farming Sierra).
What should I do with this Shadow Beldum?
A) CTM away Frustration, evolve it and use an Elite CTM to get Meteor Mash
B) CTM away Frustration and wait for December for it to get Meteor Mash
C) Purify it and use an Elite CTM to get Meteor Mash
D) Purify it and wait for December for it to get Meteor Mash