Why do you say 2 heros.
Just as you said - Ulteia is Robin-chan
Lucy is the prototype of Nami in the one-shot manga for one-piece
If you look closer you can find more.
However - that's even better for me. I love cross-dimension animeS /(manga) ^__^
EDIT: i did .. ermm.... the names and the heros.. on small images >_>