Like Cortex said, it's about balance. Legendaries are supposed to be... well, Legendary. They are stronger than most other Pokemon, but most importantly, there's supposed to be only one of most of them, like Mewtwo, Mew, Moltres, Entei, Ho-oh, etc... It just wouldn't be right to have a bunch of each of them in the game when mostly everyone would use them to win every battle they get into... You know what I mean if you've played the handheld games.

(excuse me, its LATIAS, not Yellow Latios)

(I know. Rhay does not, so he just assumes it. It's called non-meta RP)

"Nice friends you've got there Rhay. Just leaving you behind." "Shut it Geode. They're not my friends. They just "helped" me out of that hole you play boss around in." "Haha. So you noticed that... Ugh.. I guess it's time to finish this, before the real boss comes around..."
Geode jumped back up in the air. Rhay stood ready to take another explosion, but it didn't come. Instead, Geode started spinning mid-air and slammed into Rhay. He stumbled backwards, THROUGH the wall behind him. As it crumbled, Rhay charged back at Geode, hitting his boulder body. A chip fell off, leaving a bit of Geode's body vulnerable. "Damn! I've used Explode too much again... Rhay, we'll finish this later. I promise you!!" Then he dug himself down, through the concrete, leaving Rhay alone in the small building around him. Rhay looked around. It was empty.

He went back outside and looked up at the sky. He could see a couple of faint shadows flying in the moonlight. He started following them.

Geode get's hit by Zen Headbutt, but don't seem to have any reaction to it. Approaching Rhay, he talks to X, without looking at him.
"Hmpf... You are that Latios, aren't you. The one that have been held down for a while... I bet your powers are nothing now compared to back then." Only a few feet away from Rhay, he looks up at X, smilling.

"I told you to get out of here... This is my fight. Take the human..." Rhay looked over at the man lying bloodied by the wall, and at the yellow Latios attempting to heal him. "Take him somewhere safer." "Like if I would let that happen!"
Geode jumped up in the air (at least a bit), positioning himself between Rhay and X, and exploded.

Rhay turned his back to it to protect himself with his armored body.


(Your choice what you do now, but get out of there. Leave Rhay or not, I don't care)

If you've really done your research, you also probably know they will be used in events...
Why not give achievements for the whole event, like "Fought Lugia during [Insert event name]" and call it something like a pun... Yeah, I'm taking examples from WoW again...

For the same reason I think X sounds like a 12 year old kid playing CoD? Yes, seriously. Latios looks like it would sound like a 12 year old, and X's behavior... well... CoD

Rhay turned around to check out the Hybrid. Without really caring, he turned his focus back to the opening. If it wanted to hurt him, sure. The only thing he had to live for now, was life itself.

Rhay listened for a while. He could hear voices, other than the ones behind him. But they were low.
"Guys... Shh... I think I hear something."
Suddenly, a Swampert came through the opening, halting when it saw Rhay." R-Rhay..?"
Rhay could see the confusion and sadness in the Swampert's eyes as he slowly recognized it, only moments to late to react. A loud explosion made Rhay stumble backwards towards the wall. "I told her before... Escaping would only cause further pain." As the dust from the explosion blew away, the figure of a huge Golem were easy to see through it.  Rhay looked back at the ones behind him. "You should really get out of here... NOW!"

I used to have money to buy Skyrim, but then I took a x-mas to the wallet