"Elemental HERO Avian" and "Neo-Spacian Aqua Dolphin" are both Level 3 monsters, and thus interchangeable with each other via this card's effect.
This card's first effect is similar to that of "EN Shuffle".
Interestingly, both "Elemental HERO Avian" and "Neo-Spacian Aqua Dolphin" are also featured in the artwork of "EN Shuffle".
This card may be a reference to a Sentai (Ranger) transformation sequence where a hero dons his/her Ranger suit. In addition, "Cross Change" shares the name as the transformation cry in the Super Sentai Series Choujin Sentai Jetman.