I have been using my three Amiibo for Hyrule Warriors for a few weeks now, but I gave my Mario a spin in Smash Bros. for the first time last night. He's a purple costumed Mario named "Wally" for obvious reasons.
My first training session didn't go so well. I started simply trying to show him the ropes with my own Mario, covering combos, spot-dodging, and how I moved, but that just made him super-reliant on fireballs and he honestly wasn't fun to play with at all. I switched to a few other characters after and it felt like all of his tactics were completely useless. I ended up not saving any of the 35 levels I trained him up with, and called it a night.
The next morning, I gave him another go. This time, I started with my best character, then switched to Mario, and then, for about twenty levels, focused solely on kicking his ass with Wario. Around level 27 or so things really started to click with him and he was adapting really well to my tactics, not relying too much on fireballs, and doing some unconventional combos. I ended up saving this data because it feels like Wally is an interesting fighter now.