Each race has their own special forms/power-ups. These are them and how they're obtained.
Shikai- Learned when Spirit Energy reaches 600,000. Can only be used during battle. Gives a 300,000 Spirit Energy boost and increses damage and speed by 4.
Bankai- Learned by training for 72 hours or more and having Spirit Energy of 1,100,000 or more without Shikai. Can only be used during battle. Gives Spirit Energy a boost of 700,000 and increases speed and power by 9.
Additional item Shikai- Learned by having Spirit Energy of 600,000 or more and training for 48 hours with the additional item. Can only be used during battle. Increase is the same as the normal Shikai.
Additional Item Bankai- Learned by having Spirit Energy of 1,100,000 or more and by training with the additional item for 72 hours. Increase is the same as the normal Bankai.
Visored- To become a Visored you must have Spirit Energy of 500,000 or more and 10 or more damage and speed. Then you must do the forbidden and train in the Hueco Mundo for 24 hours. When you become a Visored you can never go back. It double Spirit Energy and adds 8 speed and damage.
Sanrei Glove bow- Learned by buying the Sanrei Glove from the shop, training with if for 48 or more hours, and having Spirit Energy of over 700,000. Gives 400,000 Spirit Energy and gives 6 damage and 5 speed. Permanant bonus.
Sanrei Glove removed- Remove the Sanrei glove during battle. Gives 12 speed and 12 damage. Increases Spirit Energy by 1,000,000. Effects last three days then you lose you Quincy powers unless you earn the Quincy Cross. After you lose your powers your spirit energy drops to 100,000 and your speed and power drops down to 3.
Quincy Bangle- The Quincy Bangle is an item which gives Quincy powers. After you lose your powers you can use this to have Quincy powers. It is not as good as real Quincy powers as it takes longer to charge stronger arrows and it over-heats sometimes. It increases your Spirit Energy by 300,000 and 4 damage and 6 speed.
Restored Quincy Powers- Beat Ryuken Ishida on the Boss Battles page to restore your powers to more than before. If you can't do that within the three days after the Sanrei Glove Removal you must fight him without your powers or buy and use the Quincy Bangle from the shop. Increases Spirit Energy by 600,000 and gives 8 damage and 7 speed. Permanent effects.
No forms. Must buy Spirit Energy boosts from Uruhara Shop.
Resurreccion- All Arrancars can use Resurrection. For Fraccion it increases Spirit Energy by 400,000 and increases speed and power by 6. It heals all damage when used. It increases health by 2,000. For Espada 10 it increases Spirit Energy by 550,000 and increases speed and power by 8. Spirit Energy gets a 50,000 boost when used for every rank higher up you are and speed and power gets a 1 boost for every rank higher you are. So Espada #1's Resurreccion would increase it's Spirit Energy by 1,000,000 and speed and power by 17.