At this point the shop offers:
1 Astral Coin 1000G
1 Ruby 4000G (Bloodied Ring option opens up)
1 Emerald 4000G
Notes: On turn 3, whichever side you supported in Ch 3 will show up to help you. For this reason, I suggest sending 2-3 units to the left while the rest goes up the map.
Objectives:
Bow Rune x1
Gold x2000 (in demonic, may be a little too hard to be worth with gold farm close at hand.)
Crystal Essence x2
Chests:
Astral Coin x1 (chest on right of lower left part of map)
Emerald x1 (chest of left of lower left part of map)
Elixir of Mastery x1 (chest on top right of map)
Enemies:
Astral Ring x1
Focus Rune x1
Life Essence x1
Flame Essence x1
Crystal Focus x1
Ruby x1 (super important)
Knife x1