Disgaea Dimension 2 has a new way for monster and human units to work together. Instead of morphing into weapons, monsters in Disgaea Dimension 2 can act as mounts. You can ride dragons, mothmen, and prinnies. Riding a monster increases the compatibility statistic between the two units. Let’s say you’re Etna ridding Prinny. If you defeat an enemy while on prinnyback Prinny and Etna both gain experience points. If Etna and Prinny have a high compatibility you’ll get a stat bonus too.
Disgaea Dimension 2 also has new monster and human unit combo attacks.