AKA Balance the meta a little bit or bring something that might change it completely:

Blaze, Torrent, Overgrow and Swarm now constantly boost their respective type moves, with the boost being reduced from 50% to 30%.

Tailwind now lasts 5 turns.

Scald's burn chance is reduced from 30% to 20%.

Thief now has a 50% power when stealing an item, similar to Knock Off now.

Illuminatevand Stench reduces the accuracy of moves aimed at the Pokemon to 0.9.

All recoil moves now have 50% recoil damage.

Triple Kick now has 20 power on the first kick, 40 on the second, and 60 on the third.

Iron Fist now boosts punching moves by 30%.

Serene Grace now increases the additional effect of moves by 1.5 instead of doubling it.

Hail now boosts the SpD of Ice types by 50%, similar to what Sandstorm does for Rock types.

Slow Start's timer is not reset from switching out and is reduced from 5 turns to 3.

Normalize now also boosts the power of attacks by 30% along with it's original effects.

Items that boost Gravity's, Trick Room's, Wonder Room's, Magic Room's, Terrain moves, and Tailwind to 8 turns.

Stealth Rock is now layered like spikes, it still uses SR's damage calculation with weakness and resistances, but it now takes 3 layers to deal the current amount of damage SR does, 1 layer deals 50%, and 2 deals 75%.

Embargo and Heal Block now only wear off when the Pokemon is switched out. Additionally a Pokemon with Poison Heal under Heal block will be hurt by the poison, and held items that restore HP will not work when under Heal Block.

Memento now reduces the target's Att and SpA to minimum and goes through abilities and moves that normally negate status drops such as Clear Body or Mist.

Magician now works like Trick if the user is holding an item, it still functions like Thief if the user isn't holding an item.