You should spawn inside a wooden room, if not, the coordinates are -250 3 -1268. Press the button and use the bed, you'll wake up and have the "DarkRepulser" and "Next" and "Previous".

Just drop your sword to use the selected skill. Drop either the "Next" or "Previous" paper to switch between skills forward and backward respectively. Beware, the skills have a cooldown. After you use a skill you will be notified that the skill is on a cooldown and the skill will be gray on the right side of your screen.

There are three skills, two canon, and one "semi-canon". The first skill being, Sonic Leap: You "rush" toward a random entity in a range of 10 blocks and deal instant_damage times 4. Lightning FalL: You leap upwards and hit the ground, all entities within a range of 5 blocks are struck with lightning. Death Streak: This just simulates a combo, you dash to 6 enemies and deal instant_damage times 2.