You were Dio's loyal follower. You helped her in any way you could. When she fought Jotaro you were absent, either way she came out victorious. Shortly after she won she achieved her goal of obtaining 'Heaven,' This gave her godlike abilities. After she achieved heaven you stopped being her follower since you felt like you had no use to her anymore. But one day she decided to summon you to a weird dimension.

"So, since you were so loyal to me, I've decided to reward you."

She said sternly.