This is mainly for if you use them in game or not and not so much competitively.

But yeah do you use legendary pokemon? I usually tend to stay away from most since I feel like I'm taking the easy way out and they tend to be overpowered compared to the rest of my team which makes using anything besides legendary pokemon or pseudo legendary pokemon seem pointless. I do sometimes try to make an exception though if it's a lesser legendary pokemon like raikou or uxie that have stats comparable to pseudo legendary pokemon and I really like it.

And yeah this doesn't have to only be about legendary pokemon but pseudo legendary pokemon as well like garchomp or dragonite.

I tend to use them sometimes as I feel the time put into them makes it more okay for me as they tend to evolve late in the game when all your other pokemon already are fully evolved. And they're not game breakingly powerful... Well at least not since the fairy type was introduced.

As for mega evolutions I tend to use them as I feel the 1 mega evolution per battle restriction makes it okay and they're just too cool not to use

With that said I have nothing against people who do use legendary pokemon the game is all about using what pokemon you want to use but for me I just find it a bit difficult (though if I really really like the pokemon I might try making an exception).

So do you use them? And why do you choose not to use or use them?

Until Gen V, I didn't use Legendaries (Zekrom and Reshiram in B/W don't count IMO)/Pseudo-Legendaries before the champion battle. The reason for that, well: Normally I leave Legendaries to catch them after the credits, so I have stuff to do. And Pseudo-Legendaries take A LONG TIME to get. They're normally available very close to last gym/Elite 4, and normally at this point my team is full. So yeah.

In Gen VI, my Legendary thing stands. I didn't use them in the main story. Some legendaries are not even all that powerful, but the thing is that I didn't want to use them. I guess that comes from the fact that I don't play Ubers in competitive play, so I don't use them frequently.
Pseudo-Legendaries though, it's different. You can get some of them VERY EARLY, and the Gen VI Exp. Share made everything so easy, that I couldn't help using them. My team before the Elite 4 had a Salamence, Tyranitar and a Garchomp, just cuz I can ^^

For Mega pokes... It's something extra, and i don't think they are OP or something like that, since you're limited to 1 Mega per battle. So yeah, i used them in X/Y and i will use them in OmegaRuby/AlphaSapphire ^^

Long Story short: I don't use legendaries before the Champion. You can use if you want, you play the game the way you want. But i don't use them.
Pseudo-Legendaries are no problem. They have good stats, but they aren't legendaries, so whatever. If you have patience, you can use them no problem.

I used to when I was little and I first played Leafgreen. But I haven't since then. Honestly, there are plenty of Pokemon I would much rather use, and are easier to get. Plus, most of the time, my favourites take up all the team space anyway.

I honestly don't use legendary pokemon a whole lot, I might train them every once in a while and maybe test what they can do in battle, but I don't rely on them to the point where they make up my main team. In gen 6 I already have so many powerful pokemon, with or without mega evolutions that I don't need legendary pokemon to win. I am sure people use them all the time for online battles just to be unfair and overpower everyone though. The only legendary pokemon I might care to test out would be mewtwo or Zyguard, but even then I don't think I would use them overly often. 


As for pseudo legendary pokemon like metagross, dragonite, tyrannitar and hydreigon, yeah I am guilty of using all of them, it takes some time to harness their full potential, but the end result is really worth it, and you end up with a reliable, and powerful pokemon So yeah, I tend to use those more since I only put the time in to train them. 

As for mega evolutions, I might use them, but only if I am in a pinch, or if I just want to up my stats to be on the safe side. It isn't overpowered since you can only use them 1 turn, and you are limited to having 1 mega pokemon on your team at a time. 


So to sum it all up, for legendaries, I depends on the legendary and the situation, with all of the new powerful pokemon out there, I really don't see a need to stock up on a team full of legendaries when a regular pseudo legendary team can get the job done just the same. As for mega evolutions, it is just a nice extra in case you find yourself in a situation when you could use a little more power. 

I used to always have at least 1 legend on my team that usually were OP to most characters but after I finally got bored of easily winning I started making teams without a legend to make it slightly harder but didn't change that much from when I did have a legend.
Also for mega evolutions currently I have like 3 possible ones I can use depending on situation. Sorta helps if the single mega evolution you choose ends up being ineffective against the opponent so wynaut make it to where you have a semi better chance?

I used to use legendaries when I was younger. As I grew up, I realized that using them kills the fun and challenge in Pokemon. Legendary Pokemon are very overpowered and can beat lots of Pokemon in general since they're legendary. The Pokemon with weaker/lower stats need the experience more than them. Besides, it is much more fair, fun, and challenging using regular Pokemon

I really do not like using legends because they are too OP in the game having 600 stats. I use mega evolutions because they are not too OP since you cannot even get the good ones until after the game. And pseudo legends I find okay to use since they are not legends.

I only ever use Groundon in Ruby once I capture him, because I can take down most of the Elite Four with my regular team, while Groundon takes out Drake. But I normally don't, as it does kinda kill the fun in Pokémon.