User blog comment:DarkJester4114/Another Interesting Idea by DarkJester4114/@comment-119.74.222.198-20140813105441

Maybe instead of double type units, we could have units that can evolve into one of two given types?

eg : Unit 1 has two types, fire and water , but only allow one type when evolution from (3 to 4 star or 4 to 5 star or 5 to 6 star ) so maybe this is better? You could own the same unit but with different types...