How would he know about that from the start? I doubt anyone outside of guys like Arceus knew that to anyhow tell him. And you aren't born knowing everything.
That Mew was his equal in strength or at least close to it?
One of the very first things that the scientists tell Mewtwo when he breaks out of the tube is that he was created from Mew's DNA and was made stronger. He even boasts this to
Mew itself.
Or that Mew would dodge his attacks?
Well, I'll give the first two Shadow Balls, as the first one
almost hit Mew (it hit the bouncy bubble Mew was playing on) and the second one was before Mew started to dodge. But
once Mew first teleported away from the second Shadow Ball, there's no excuse for Mewtwo to pretty much blindly throw them where he thinks Mew is (yes, that's what he
did; before he fires the third, he states "Over there...?" in the original Japanese film while the dub keeps him silent) instead of doing what he did
later and fire it while closing the gap between them and give Mew no time to dodge it.
Yeah and considering how light he is, it would stop on the boots already (still don't get it why he is so light despite being heavy in Pokemon games and him ensuring safe landing through levitation would only explain his low falling speed).
Mewtwo is in a constant state of levitation in Smash, which pretty makes the concept of "weight" to be pointless (weight is the force of gravity exerted on an object; levitation
defies gravity).
And then there's the fact that "weight" in Smash doesn't even refer to
actual weight, but instead knockback resistance. Mewtwo has less of that due to that aforementioned constant state of levitation. This is the exact same reason Rosalina is so light (though through anti-gravity, not telekinesis).
Still, if he would know that opponent can give him face full of boots, disrespect and dark energy, a cracked spine or complete and utter annihilation through a punch, i doubt he would just slowly move around like he does since Melee (outside of wavedashing of course, which is exclusive to Melee anyway) even though that clearly puts him into danger of everything listed above.
Mewtwo's
a lot faster than in Melee.
After it was getting clear that Mew won't be that easy to beat, he didn't continued to do what he was doing since that clearly wasn't effective. When he found out that it could also attack him, he stopped fooling around and suddenly DBZ.
Response by sentence:
-Should have
already been damn clear Mew would take effort to defeat.
-You literally restated a point I made before.
-Not only was Mewtwo aware Mew was capable of fighting back, he was questioning why it
wouldn't (until it did). And stop bloody calling their fight "DBZ". It was nothing even remotely close to it.
Why wouldn't same happen against other characters in SSB, who can both dodge his attacks and attack him? All that would be required is stay out of their range all of the time. He at least has projectiles, unlike characters listed. That is within his limits.
Why? Because:
a. This isn't the damn anime.
b. Most characters would have a
very hard time dodging and/or getting an actually decent hit in during an
actual fight (i.e. not going by fighting game logic where anyone can manage to defeat
anyone). Only scenarios like your proposed
three on one fight would have any shot depending on who they are. Hell, in an actual fight scenario, only a select few could even permanently harm Ganondorf before he outright kills them due to the Triforce of Power. (Note,
harm. That doesn't mean they couldn't send him flying off a battlefield if they had enough force)
Correction; they don't have projectiles
in-game (except Bowser
does WTF). Ganondorf has his own energy balls and Captain Falcon has the laser pistol he has holstered to his side.
At this point, the discussion is not even about
Ridley anymore but going back and forth about
Mewtwo (and I can only assume Ganondorf now). What point is there left in this?