Hi man! I don't really know how much would you like to spend to play, but this deck is lacking several things in my humble opinion.

1. Both Spear of Heliod and Hall of Triumph are legendary. Yo don't have a way to cycle cards or draw more than 1 each turn, so when you have one of them in play, the other becomes a dead card in hand. 1 is just enough. Your deck shouldn't depend on them to win.
2. Astral Cornucopia is totally useless in this deck.
3. Include 4 Arashin Foremost and 2 more Dragon Hunter. I'm not so sure, but I'd give Dragonscale General and Sightless Brawler a try.
4. What are Radiant Fountain for? You need to attack as fast as you can, a tapland won't do any good. And you shouldn't care abou yur own life, as you'll be hitting your opponent faster! Include Nykthos, Shrine to Nyx instead!
5. Triplicate Spirits is very slow, despite its 'Convoke' ability. Use those slots to include removal spells, like Pacifism or Banishing Light. They also give Heliod, God of the Sun a boost in devotion.