Mega Probopass:
Type: Rock/Steel > Ground/Steel
Ability: Magnet Pull/Sturdy/Sand Force > Filter
Stats:
HP: 60 > 60
Attack: 55 > 75 (+20)
Defence: 145 > 155 (+10)
Special Attack: 75 > 95 (+20)
Special Defence: 150 > 160 (+10)
Speed: 40 > 80 (+40)
New moves: None
Thoughts: Probopass's stats are strange, in that its stats are really polarizing. Those defences are pretty phenomenal, but if you give it a good SpA, it then becomes a beast of a wall that's also going to hit you really hard with Rock/Ground/Electric coverage. But, buff its defences and the low HP doesn't actually matter because nothing will kill it, ever. So, I decided to just give it minor buffs to everything, enough to make it viable but not enough to make it go over the edge for me. I also didn't add to its movepool for the same reasons, I don't want it to go overboard. Removing the Rock type and giving it Filter
may be too much, but it does still have a fair amount of common weaknesses, just less so.
(Wish this guy had a 2D sprite)
Mega Alolan Golem:
Type: Rock/Electric > Ground/Electric
Ability: Magnet Pull/Sturdy/Galvanize > Magnet Pull
Stats:
HP: 80 > 80
Attack: 120 > 150 (+30)
Defence: 130 > 140 (+10)
Special Attack: 55 > 55 (+0)
Special Defence: 65 > 75 (+10)
Speed: 45 > 95 (+50)
New moves: Zing Zap
Thoughts: Physical electric trapper. Any attempt to turn this into a special trapped would just make this a weaker Magnezone, so I went the other way and made it Physical. Ground/Electric over Rock/Electric here gives it STAB Earthquake and a Resistance to the steels it's supposed to trap, helping it out a lot. The increase in speed was so it could outspeed other Steels as opposed to having to bulk through them.
Mega Magnezone:
Type: Electric/Steel > Electric/Steel
Ability: Magnet Pull/Sturdy/Analytic > Magnet Pull
Stats:
HP: 70 > 70
Attack: 70 > 70 (+0)
Defence: 115 > 135 (+20)
Special Attack: 130 > 170 (+40)
Special Defence: 90 > 120 (+30)
Speed: 60 > 70 (+10)
New moves:
Thoughts: Not much to say here, Magnezone's already a great Pokémon and this just lets it do what it needs to better.