The ending song for this episode was "Everlasting Song" performed by FictionJunction ASUKA.
This is the episode that starts a chain reaction: Viro realizes that she truly does love Cou. We see that she starts to wedge herself between Cou and Ren.
This is the first time we see Ren truly react to Viro and Cou.
Ren takes a step between the children and the "bullies" of the town.
First appearance of Ren's Wind Armor.
This is the first time that we see Cou's skills in repairing and maintaining an airship.
This is the first time that we see Cou and Ren really become a single fighting team with devastating results.
Sting Raids have a huge drawback, their implanted abilities put a huge strain on the body and mind. This may cause death in some cases.
Every Edel Raid has a special stone somewhere on their body called an Elemental Gelade. This stone is proof of being a real Edel Raid.
Parl is a Sting Raid which is a fake Edel Raid.
Imitation Gelades are inserted in a woman and she has the abilities of an Edel Raid, but she is still a human.
They can have as many Pleasures as they want.
After Cou Reacts with Ren, he has become her Pleasure, which is a person who has Reacted with an Edel Raid.
Ren is an Edel Raid--that is a being who is able to React (or merge) with a human and become a weapon. They can use "songs" which are magical spells. They can only have one Pleasure at a time--to have a new Pleasure, the first one must die.