s h i _ i e i _ i _ a _ a _ a n a d u
l-------------------
l l
l \ O / l ( ) l / l l ------------------- Letters used that aren't in the answer: O, R, L, T, P, W, G, B, F
The most vaguest hint: They're 4 letters left, meaning there is one letter that is going to appear twice.
Final boss of a game. Green Haired.