So many silly things on this page. Yoshi has amazing untapped potential IMO, and I say that because I main Yoshi. Yoshi can kill many characters at 0% with his Dtilt gimp, has amazing DJC abilities, a unique ability to DJCC and parry, best light shield in game, very versatile projectile(but laggy and not good for edgeguarding at high % or on non-fastfallers) and can instant ledgehog. Those pros stated, he also has many huge flaws, such as no third jump, relatively easy to combo, relatively bad priority, few recovery options, inability to jump (and by extension wavedash, upsmash, or up b) out of shield, and the worst grab in the game (tether with less range than Marth's, does 4% and over 70 frames running or standing).
Also, you're asking in the OP for the posters to predict who will develop the techniques? And give a random example of Mewtwo's shadow ball. . . No. Straight up nonsense OP, but a good idea. The Toasty guy, he is wrong about Yoshi, in every way.