A German "paper ship" design with a unique A-XY turret layout that was added to Azur Lane as part of a collaboration between it and World of Warships. Roon never saw much in the way of development, and no ship of her class was even considered, nevermind ordered or laid down.
Roon is portrayed with blonde hair and brown eyes adorning a gentle face that hides a highly-sinister personality. Similar to Graf Zeppelin, Roon is sadistic, relishing in bloodshed against her enemies, and even expresses willingness to attack her own allies. She becomes rather yandere for the Commander with enough affection, and will merrily kill anyone who attempts to come between the two.
In reference to World of Warships from which she's taken, Roon gains a skill based off of one in the game. In this case, she holds the "Expert Loader" skill, which translates into Azur Lane as her changing shell types between high explosive and armor-piercing on the fly.