to S rank
The reason I'm starting out on this Pokemon is because I have no clue where to start, and I like Jirachi. This Pokemon is so good. It has like 8 different sets, but I'm going to talk about a few of them. The first set is Scarf, which is my most favorite. This Pokemon literally has no switch-in (in theory) if you play it right, because it has access to fast U-Turn. This, when paired with rocks, will continue to weaken Jirachi's would-be-switch-ins, until they're completely useless. If you want to do that but not switch out, just click Iron Head a few times, which flinches 60% of the time by the way. You also have access to a coverage Punch move of your choice, the most common being Ice Punch. Having that slot really can change what a team loses to and what doesn't, so it's smart to choose wisely with the elemental punch. For example, my team was fairly weak to Scizor, so I decided to run Fire Punch. Another one of my teams were weak to Mantine, so I ran Thunder Punch. This slot is there for team coverage. The last move is my favorite because it really breaks Mega Latias, and that's Healing Wish. Healing Wish is such a good move, and I'll tell you why. Say your wall gets hit by toxic, and your Jirachi is at low health. No worries there, just click Healing Wish and recover your wall. A Pokemon is about to die to hazards? Healing Wish it up. Healing Wish is an emergency move that you'll find is really good in so many situations. The only problem I see with the Scarf set is other scarfers, mainly just Infernape and the infamous Scarf Weavile.
What about it's other sets? It also happens to be a great Rocker, Wish Passer, Sweeper, as well as utilizing Calm Mind, and even being able to run an e-belt lure set. You could also run Z-Happy Hour, but I personally don't like to use that. The point is, this Pokemon is so versatile, and it's really hard to cover all of it's sets, not just in text, but in battle as well. Having 100 across the board really helps too, as it allows you to run offensive sets just as much as defensive ones as well.
All in all, this Pokemon can fill multiple roles with no issue. Thanks to it's 100/100/100/100/100/100 stats, it's able to run a multitude of different sets, and it's wide move pool only helps. It's also a Steel type, which you're really required to run now,
especially now. That really sounds like an S rank Pokemon to me.
to C+
Ok let's get this garbage out of the way... I really don't see a reason to use this Pokemon. I know it's Special Attack is really good and it's really bulky but the two moves it runs are Dragon Pluse and Volt Switch, and you're really forced to use RestTalk since if you get worn down you just have to sit there and die because of your poor speed. I guess it could 1v1 bulky waters, as well as Tornadus and Aggron, but I can't see this Pokemon doing much more because while it doesn't have many weaknesses, it doesn't have many resistances either, which leaves a lot of other types doing neutral damage.
Basically, my point is, for such a slow Pokemon, it's typing isn't that good, and why run something with such good special attack and so slow when you can run something that sacrifices a little Special Attack but gets faster instead. This Pokemon is very outclassed in it's roles, so
I think it should be C+ because of this.
to A+
I originally said that this Pokemon would be broken, no question. But I soon came to realize that there are several ways to work around this Pokemon, and that it unfortunately suffers from 4MSS. The idea here is, no matter what, this Pokemon requires support. Even if you run HP Fire, you lose to Mega Steelix, if you run Focus Blast, you lose to Scizor. There are a few Pokemon that can switch into a Hyper Voice, some examples are Empoleon and Alolan Muk. So, realistically, you'll want to pair Gardevoir with an Electric type, a Ground type, Magneton/Fire type.
Now, I did forget to mention what this Pokemon does in general, which is spam Hyper Voices. Mostly everything is 2HKOd except the Pokemon I mentioned above. It's speed is above average, and it's special attack is out of this world. It also has access to Calm Mind to set up, Taunt, to shut down Blissey and Alomomla, as well as Will'o'Wisp, to shut down physical attackers. So, don't think this Pokemon simply runs 4 attacks. It also requires a Calm Mind to really get going, which is another reason I don't want this thing straight to S rank for those who think this thing is unbeatable.
Overall, Mega Gardevoir is a great Pokemon on the surface, having incredible overall stats (did I mention it's spdef?). It also has access to Set Up moves, Taunt, and Will'o'Wisp, making this Pokemon seem completely broken. However, if you look into the Pokemon more, you'll realize that it needs a bit of support to really sweep/clean teams. Because of this, I think
Mega Gardevoir should be A+.
to A+ rank
This Pokemon has one set and it loses to nothing (almost nothing lol.) It runs Calm Mind, Stored Power, Ice Beam, Recover, which pretty much walls then sweeps everything not named Empoleon, Weavile, or Alolan Muk. Because of this, I recommend a Steel type (Jirachi, and I'll explain soon) as well as a Ground type. Your Steel type should be Jirachi because you can provide Healing Wish support in case your Latias is too weakened or statused.
Not much else to say about this except
I want this A+ like Mega Gardevoir because like Gardevoir, it requires a bit of support so it can do what it does.
That's all I have for now, I have little to no experience with the other ones, so I decided not to embarrass myself and post them.