So everyone's ignoring the songstresses ability and the majority seems determined on her physical form.
I didn't see this and if it was posted I apologize, but I just think wasting a turn with Relic Song for a 10 (boosted to 20% due to Serene Grace) letting your opponent do whatever they want is a really bloody bad idea.
Especially with such a diverse special movepool where leaving it in Voice form can easily work once you ignore Relic Song:
Meloetta-Aria form
Serene Grace
Timid
@Expert Belt/Wise Glasses
4HP/252 Sp. Atk/252 Speed
Shadow Ball (40% chance of lowering the target's Sp. Def)
Charge Beam(140% chance of raising Sp. Atk one stage/Guaranteed)
Hidden Power(Fighting)/Hidden Power(Ice)/Hidden Power(Fire)/Focus Blast/Grass Knot
Substitute
It's going to have to hide behind a substitute unless something else is going to be tanking hits for it, it doesn't have the bulk, but I still think it's a waste of time when the songstress' sp.atk is already that high and can do some severe damage. Besides looking at this thread most people are going to expect the switch and bring in something to deal with a physical hitter.
Shadow Ball has a 40% (a 2 in 5) chance of lowering your opponents Sp. Def, and it let's you take care of a few things.
Against a Max Sp. Def Gengar Shadow Ball does 55%-66% of it's health as damage if Wise Glasses are used. Expert Belt raises it to 61%-72% which is still a guaranteed 2HKO.
Against a Max Sp. Def Frosslass Shadow Ball w/ Wise Glasses does 55%-65% of it's health. With Expert Belt 59-70% of it's health which is still a guaranteed 2HKO.
The problem now comes with Jellicent.
Bulky Max Sp.Def Jellicent can take a few Shadow Balls even with Wise Glasses or Expert Belt. Against Jellicent Shadow Ball w/ Wise Glasses does 36-43%. Expert Belt only moves that to 39%-46% forcing Jellicent to be a 3HKO by it, two maybe with the lowering of Sp. Def barring Substitute.
Now onto the Psychics which is where this also becomes useful:
Max Sp. Def Espeon taking a Shadow Ball when the user is holding Wise Glasses puts it at doing 46%-55% damage as a 7% chance to 2HKO. Expert Belt boosts that damage to 50%-60% as a Guaranteed 2HKO.
Reuniclus is another Pokemon that hurts this set forcing a 3HKO if Meloetta can even stay around.
Shadow Ball w/ Wise Glasses does 39-46% damage. Expert belt boosts it to 42%-50% so barring a crit Reuniclus can sit there and Calm Mind and make her say bye bye.
Alakazam is yet another 2HKO. Wise Glasses allowing Meloetta to do 53%-63% damage to it, while Expert Belt boosts this to 57-68%.
And yet another 3HKO is forced by Celebi as Shadow Ball maxes out at 37-44% w/ Wise Glasses or 40%-48% with Expert Belt.
Onto Charge Beam.
Charge Beam isn't the greatest move for it's power but it does the important job, the important job of raising Meloetta's Sp. Atk stage by 1, each time used, and after a couple, it could be a nightmare if Meloetta can stay behind a substitute. That's the entire point of Charge Beam, you'd use it on a switch, when behind a sub, to boost Meloetta's Sp. Atk because that's the entire point, to build it, while Calm Minding will have Tyranitar/Terrakion/any Physical Sweeper trying to wreck you. The only things worth mentioning where Charge Beam could possibly be useful are Gyarados or Tornadus.
Charge Beam vs Gyarados does 47-56% damage when the user wields Wise Glasses, 52%-61% when holding an Expert Belt.
Vs Tornadus 30%-35% w/ Wise Glasses. Expert Belt minimally raises that to 33%-38% damage.
Beyond these two, maybe against Jellicent or Tentacruel as they try setting up to raise your Sp.Atk to a decent level although it barely does damage to them sitting around 25%-30% damage before a boost with the items.
There's a lot to say with the third moveslot. Focus Blast is powerful and will let you hit for a good amount of damage, but the accuracy is risky at 70% and if you miss you may as well say goodbye. Hidden Power Fighting can make this useful as it will allow you to hit the same Pokemon without missing at the cost of some damage, Normal/Rock/Steel/Ice/Dark is nice, hitting 5 types supereffectively. The problem is, as great as moves like Close Combat have become, from the OU list you're hitting:
Hydreigon
Scrafty
Mamoswine
Heatran
Ferrothorn
Cloyster
If you really wanted you could try and dent Chansey and Blissey although that's for Physical Sweepers.
Hidden Power(Ice) lets you hit the following from the OU list supereffectively:
Hydreigon
Haxorous
Dragonite
Salamence
Latias
Latios
Tornadus
Virizion
Breloom
Venusaur
Dugtrio
Donphan
Landorous
Gliscor
Hidden Power Fire lets you hit the following from the OU list:
Forretress
Scizor
Breloom
Venusaur
Ferrothorn
Skarmory
Metagross
Jirachi
Lastly you have Grass Knot, not the greatest but can help with coverage. Seeing as it falls heavier foes such as Terrakion (2HKO/ 56%-70%), Tyranitar (2HKO/ 50-59%), Gastrodon (2HKO/50%-59%).
So it really comes down to preference and what you don't want to be walled by. Based on numbers I'd go for Ice since Dragons can be a nightmare
Substitute is supposed to keep you alive, while something else heals/tanks for you as much as possible because before at least 2 Charge Beams I doubt this is going to work well.
In addition to that why not Choice Scarf/Choice Specs/etc? You're going to need versatility in order to meet against the team, if you're locked into the weakest move on this set (Charge Beam) it's not going to help, and if you're using Substitute on a set where you'd use a Choice Item there's something wrong with you. Other mons should fill that place, especially with Item Clause. For example Dragonite tends to be used physically but given enough speed and the right environment a Choice Specs one can be used well only due to it's large move pool.
Another thing to note that this was all calculated without SR/Spikes damage. I also don't know how accurate these numbers are but here's the calculator I used:
http://kalashnikov.pokecenter.ru/damage/
Anyone see anything wrong?
