Sylus, The Hawkeye (Support/Marksman)

I had this Idea for a Support/Marksman based a bit off of Native american culture where his main source of health/damage is mana based and I believe this would be a great Idea with a bit of balancing. If any of you guys have ideas on this concept please feel free to suggest things.

Passive - Basic attacks scale off of mana rather than AD, basic attacks and spells from enemies drain your mana pool and then your health when your mana hits 0 your mana bar cannot be regenerated except by outside means such as mana pots. Sylus does not gain additional health as he levels up.

Q - Wounding Strike - Throws a medium ranged Tomahawk to slow enemy champion for 20/25/30/50/60% for 2 seconds has a 5/10/15/20/25% chance to stun for 1.5 seconds. Deals damage based on how much mana you have. W - Blessing of Tirawa - Gives ally/self a Shield that blocks 15/25/35/40/50% damage from enemy spells for 3 seconds Basic attack damage is unaffected E - Depletion Zone - Sylus slams a Tomahawk into the ground creating a circular space that drains Mana and Energy per second and gives 10/15/25/35/50% to you R - Battle Vision - Channels for 3 seconds and launches a Shining Tomahawk high into the air to reveal the entire map for 10, 20, 30 seconds (CD 60/80/120 seconds)