Gamabunta, this would make this deck a "Kog worthy" deck, not a tier 2. A Kog Worthy deck means exactly this: the deck is good enough to make you reach KOG if you play it right.
Tier 3. It can't compete against Blue Eyes or DNA Buster Blader. I like it, though. And I've also add one Blackwing - Mistral the Silver Shield, because Blizzard can't be special summoned by Shura, and this deck depends a lot on bringing your big synchro monsters early !
I think it's tier 3 at best. I don't see any win condition without their big monsters, nor any way to deal with backrows/ protection. Even the lv8 synchro is hard to bring out, compared to dragunity.