Smogonite here, and let me just say upfront that balancing is hard without the ability to conduct multiple tests. Anything that looks fine on paper could be broken in practice, or the inverse, useless. I can however, give some general guidelines that should help you balance things.
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Base stats
- Typically you want a fully evolved pokemon to be between 450BST and 540BST. You can go lower or greater, but this is the typical range of MOST pokemon. I should also mention that in competitive pokemon, most pokemon are above 500BST.
- 580-600BST are reserved for Psuedo-legends like Garchomp, and lesser legends like Terrakion and Mew.
- Major legends have a 660-720BST, but the most common for boxart legends is 680.
- For attacking stats: 100 is considered to be slightly above average in battle. 130 is considered very good, and 150 is considered overpowered by most standards, mostly ubers like Palkia have an attacking stat at that range.
- Defensive stats, including HP, are by contrast a lot more biable in terms of stats. Defensive pokemon usually depend more on typing and ability, though larger stats are still important.
Moves and Abilities
- Consider access to moves when determining balance. EG: does this Ground/Fairy type pokemon have Nasty Plot, access to Earth Power and Moonblast with a high speed? If so, it has perfect coverage and can sweep the entire game. Consider getting rid of Nasty Plot.
- If a pokemon has perfect or near perfect coverage, consider if it can be reasonably stopped by other pokemon you have made. If it can't, then in theory nothing could stop it from sweeping.
- Some abilities are just broken by design: Shadow Tag and Huge Power come to mind. Unless you can get a clever workaround, just don't use them at all.
- Powerful abilities, such as Regenerator or Magic Guard, are very useful and thus shouldn't be placed on already powerful pokemon, such as the 600BST Garchomp. Consider instead using them to make weaker pokemon a lot better.
- Conversely, weaker abilities such as Blaze and Hyper Cutter can be freely placed on powerful pokemon without worry, though be careful not to make the abilities too useless on that pokemon. EG: Merciless on Toxapex. Like... why, Trollfreak?
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In conclusion, Balance is hard. Sorry. But, try your best and just have fun. Each time you make a pokemon that you think may be too powerful, ask yourself the question "Is there anything that can beat this normal/if it sets up/can 2HKO it (with defensive pkmn)?" If the answer to that question is "No" or "Only under very soecific circumstances", then consider reworking that pokemon.
As a conclusion, I'll make a Fairy/Ground type from your example as my balancing act example as a normal pokemon.
Mystarea (IDK it's off the top of my head)
Fairy/Ground
- Immunity/Vital Spirit- (Abilities chosen to help the pokemon defensively)
100HP/45AT/75DF/120SA/70SD/87SP- 497BST ( good SP that can outspeed things while still being outspeed, and really good SA)
— MOVES: Moonblast, Earth Power, Wish, Protect, Refresh, Hyper Voice, possibly Rock Polish (The important thing here is to not give it both a SA boosting move with a SP boosting move, only one or the other so it can have counters and checks)
I hope my comment is of some help to you.
