Alistar Passive Revision

Alright, with the Alistar VU coming up, I thought it was the perfect time to suggest my idea for a possible revision of his Innate Passive to make it more useful as a support and define him more as a character. Without further ado, here goes:

Trample When an allied champion uses their basic attack against a champion, they are "Marked with Red" for X seconds. When Alistar runs in the direction of the enemy champion that is marked, he gains X% Movement Speed, and the ability to move through units, additionally dealing damage to units he passes through. The same enemy cannot receive a Red Mark for X seconds after the mark fades.

So, what do you think? If anything, it provides enough utility for him to get in range of his opponents before bashing every which a' ways. Just a concept I thought of, let me know what you think!