>>29066712Legal Version:
Catch'em all without trading
Important Trainers have stronger teams, and many will now use Mega Evolution
Six new TMs: Fire Punch, Thunder Punch, Ice Punch, Sucker Punch, Drain Punch and Giga Drain have replaced six less useful TMs (see the documentation for details)
All Mega Stones (except Mewtwonite X/Y) are obtainable before the Elite Four
All Fossils are held by wild Pokémon in or near Glittering Cave
Competitive items can be found on wild Pokémon or in Snowbelle City
All but two TMs are available before the Elite Four
All changes except the rivals' teams are fully documented
Reasonable level curve designed around leaving the EXP Share on at all times
Weaker Pokémon level up faster, making them more powerful than usual later in the game
All level up learnsets have been updated to match ORAS where possible
Many Pokémon now have their Hidden Ability available as one of their two regular abilities
Most Pokémon will be able to learn egg moves by level up, or from the move reminder
Rebalanced Version:
All the features of the Legal Version
Type, base stat, ability and movepool changes have been made to many weaker Pokémon, with the intention of making them more fun to use (see the documents for details)
Some weak or useless moves have been changed; for example, Cut is now a Grass-Type move that will always result in a critical hit, and Leech Life now has 75 base power
Insanity Mode:
All the features of the Rebalanced Version
Rivals, Gym Leaders, Team Flare leaders, etc. all use more powerful teams, sometimes including Legendary Pokémon. Their teams don't always make sense, but they do make the game significantly more challenging. See the documents for details.
Check this link for all the details,not sure how hard Legal and Rebalanced are
https://www.pokecommunity.com/showthread.php?t=362505 
