Actually, can you do this in vJASS for me?
Unstable Current
Description: Tonitruum's very body is a constantly shifting miasma of dark energy. This unnatural state allows him to move with supernatural speed, and any foe foolish enough to launch a direct magical assault against him will have their boldness rewarded with a shock of purging electricity.
Target: Enemy Hero
Level 1 = 0.4 Duration, Purge: 3% Movement, 40 Damage.
Level 2 = 0.4 Duration, Purge: 6% Movement, 70 Damage.
Level 3 = 0.4 Duration, Purge: 9% Movement, 100 Damage.
Level 4 = 0.4 Duration, Purge: 12% Movement, 130 Damage.