Grounded Mario!
Mario is jealous of the sneakers.
No, of course this is a bthrow. Thankfully for us, it is quite a common trait for most elements of Mario's game to have low range. His grab range is no exception, being one of the shortest in the game. His grab game is pretty poor in comparison to the rest of the cast, in that they don't really lead into anything. Well, u/f/b don't, anyway. Bthrow will be killing you at about 160% dependant on where you are getting grabbed on the stage, so watch for it.
Dthrow at a low percent is what most good Mario's will use, hoping for it to lead to a chain of utilts. Thankfully, we have a spring with invincibility frames at start up, so you shouldn't be taking too much damage from a dthrow. Mario's other tilts are pretty poor in comparison to utilt, with dtilt popping the opponent right up in front of him and giving too little hitstun with too long an ending lag, it usually results in Mario getting punished. Ftilt is okay, as far as attacks go, it's nothing special.
Fireballs may be used to force an approach, but thanks to spinshot and having a high ground speed in general this isn't difficult. Where Mario really shines is in his smashes. His up smash has good priority, and disjointed range to the sides of him and comes out fast, making it pretty difficult to avoid and punish. His dsmash comes out very fast from a spotdodge, and considering Sonic's dsmash is slow to start up anyway, you don't want to be caught in a spotdodge war with him. His fsmash kills faster than anything Sonic has when aimed upwards, and also has more range when stutter stepped than Sonic's own stutter stepped fsmash. Thankfully, a Mario won't be using it too much during the match, he'll be saving it for the kill.
So, how do we counter this?
Suggestions on moves, quotes, that kinda thing will go here. Should we keep grounded or aerial? That kinda thing.
Aerial Mario (Jump Man!)
Mario's are seen as a far bigger threat in the air then on the ground, and for good reason. Dthrow is usually used to get the opponent into the air, then they are followed with nairs, and uairs. Uair is a great move simply because of the speed and range it gives, allowing Mario to somewhat effectively juggle in the air. It doesn't even need to be used against an aerial opponent, it can be used to approach a grounded aerial with. Nair is a sex kick, it's knockback is higher when the hitbox first comes out then it is when the hitbox has been out for a while. It can be used to SH approach, but it doesn't have great range despite having good priority, which means if it's telegraphed it's fairly easy to shield grab.
One aerial less susceptable to shieldgrabbing is his dair. Now, shield pressure is very important for Mario's approaching. You know the characters that love to shieldgrab Mario because of his low range? Well, shield pressure allows that to not happen, and D-air gives out that shield pressure they need. They abuse it on those who love to abuse the shield grabbing. Also good for happy-spotdodgers, and it's last hit has big priority and sends the opponent up into the air, where Mario prefers them to juggle.
Bair is a good move for obvious reasons. Can be used offensively and defensively, has big range, good priority. It's a very safe aerial, Mario can float in and glide in and out bairing and it's pretty hard to shieldgrab him for it. Mario's Cape is mentionable here, for edgeguarding and projectile swatting, as are his Fireball's which he can fullhop and shorthop to force approaches. However, these two specials aren't really god for much in the Sonic v Mario match-up so don't need to be reviewed too in depth.
How would we counter this, guys?
Steak