Try and identify the similarities and differences in the Dept. Heaven games.
Action RPG:
KitN has more action elements than Yggdra Union has more action elements than Riviera.
Retry:
You can retry if you lose.
Skill Attacks:
Each game has some version of something called a skill attack. That isn't too surprising because many RPG feature skill attacks (they're not always called that though). Rivera has "Over Skill," Yggdra has "Card Skill," and KitN has "Skill Attack."
Items:
Some of the items are recycled between the games.
Enemies:
Some enemies are recycled between the games. Skeleton in particular appears in all three; Witch, Knight, Slime, Spider, and Troll appear in both Riviera and KitN. Catapults appear in Yggdra Union and KitN.
Enemy behavior:
Enemies in all three games have a RAGE mode in which they are more powerful. In the first two games, enemies have a MAX mode where their power is at max.
Something Angelic:
Riviera has Archangel. It makes many references to "the gods."
The final boss in Yggdra is
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Archangel.
A couple of characters in KitN are mentioned as being Angelic.
Main Character is a girl:
Ein is a girl.So is Yggdra and Maria is too. You might think Wilmgard is the main character, so this might not be true for KitN.