Diggersby-Mega
Ability: Pickup/Cheek Pouch/Huge Power----> Simple
Typing: Normal/Ground
Stats:
HP: 85 ----> 85
Attack: 56 ----> 116 (+60)
Defense: 77 ----> 97 (+20)
Special Attack: 50 ----> 50
Special Defense: 77 ----> 97 (+20)
Speed: 78 ----> 78
Base Stat Total: 423 ----> 523
Movepool Additions: None :)
Description: As a Normal type, Diggersby is a simple mon. It continues is duty as a digger of tunnels with no intentions of being powerful. But being Simple is actually what makes it powerful.
Competitive: Diggersby is a powerful set-up sweeper. One Swords Dance triples its already good Attack stat and Agility let's it out speed almost the whole metagame. Access to those humongous boosts gives Diggersby the luxury to invest on bulk. A tripled Attack boost lets even its puny Quick Attack sting! Normal/Ground STABs provide good coverage with Wild Charge to hit Skamory. That being said, this Mega is by no means perfect. It needs to boost to be powerful and fast meaning the opponent can take advantage on turn one. If Diggersby want to be fast and powerful at the same time then it has to give up a STAB or coverage move, leading it to a slight 4MSS.
Blissey-Mega
Ability: Serene Grace/Natural Cure/Healer ----> Thick Fat
Typing: Normal/Fairy
Stats:
HP: 255 ----> 255
Attack: 10 ----> 20 (+10)
Defense: 10 ----> 20 (+10)
Special Attack: 75 ----> 115 (+40)
Special Defense: 135 ----> 175 (+40)
Speed: 55 ----> 55
Base Stat Total: 540 ----> 640
Movepool Additions: Moonblast
Description: Blissey is now fluffier and cuter than ever. Its fat layers are so thick that it can no longer feel the pain of extreme heat and cold. Scientists have also discovered that Chansey and Blissey's egg have a connection to the moon. The moon sends signals to the egg to give it more nutrition.
Competitively, Blissey is now bulkier and has more resistances. Previously it had zero, but now it has four! That is all thanks to its new typing and ability. Also, it gets a new dragon immunity in addition to its existing Ghost immunity. Its Special Attack also gets a significant buff, meaning it can also work excellently as a bulky attacker thanks to its wide offensive movepool. Despite all its buffs, I still don't like overpowered Pokémon so I didn't raise its defense that much. Any moderately powerful physical attack will still dent it. As with any other defensive Mega, it also loses its Leftovers recovery so it will be more pressured to heal itself. It also loses Natural Cure, though it can still Heal Bell. Overall, it's a Blissey with beefier special stats and a lot more resistances.