Protection

Gain a +1 to AC and lower damage taken by 1 for every stack. Lose stack at turn end.

Haste

Increase initiative by 1 and movement speed by 10ft per stack of Haste. If movement speed doubles your base movement due to Haste stacks, you may ignore difficult terrain and may disengage as a free action. Haste is reduced to 0 at the end of your next turn. Only one stack of haste may benefit from Untraceable Speed's speed increase.

Offense Level Up

Increase damage rolls by one dice tier per stack. Lose stack at turn end.

Defense Level Up

Decrease damage dice tier of attacks taken per stack. Lose stack at turn end.

Aggro

While you have Aggro stacks, all hostile creatures must make a Wisdom saving throw when within 10ft of you at the start of their turn. The DC for this save is equal to 10 + Number of Aggro stacks on self. On failed save, creatures must target you with their next hostile action. Hostile actions are defined by any attempt to harm or debilitate a creature. When a creature fails this save, they are immune to it for the next minute. Aggro stacks decrease by 1 at the start of the user's turn.