He's well known in the academy for leaving many girls weeping in the girl's bathroom for a good amount of years, and is disliked by much of the student population for many reasons. Was apparently the victim of bullying and fistfights during his first year of school.
He is not at all shy about the fact that he has had sex before, and will openly tell the player character that he is not ashamed of all the people he has been with. He used to date Angela, before she publicly broke up with him, which she will gleefully tell you when she sees you on a date with him later on in the school year. He also briefly dated Musette before she was expelled from the academy, although he couldn't tell you why she was expelled.
Spoilers ! click expand to burn your brain ------>
He's apparently bisexual, if William's confession about their dating in their freshman year is any indication. If he isn't involved with the player character, there are rumors late in the year about him "taking advantage of a freshman boy". This may be another nod to his sexuality.
He gives off a rather mysterious vibe, or so the player's Character says in her diary. He delivers many warnings to be careful, that it's dangerous in Iris Academy, and that the teachers can't be trusted - but only in a very enigmatic way.
According to William he never goes out on school field trips, and doesn't take part in any clubs. He seems to spend most of his time flirting with girls.
He is a charismatic and talented actor all in all.
Damien makes for an interesting challenge in dating. His path is the easiest to start, but it's also the easiest to break. And a lot of Damien events override those of others. He's also unique in that he has no "just friends" scenario: You either have to be dating him, or you have to break it off with him completely.
Spoilers ! click expand to burn your brain ------>
(Optional) During the first week of school, you can meet Damien by taking a Gym Class.
Agree to take his hand when the initiation begins. Refusing him twice will lock you out of his path (and net you Weird Points)
Your choice in the love letter you write to Damien will affect what present he gives you later. The outcome of the letter being discovered will not affect his path.
You can choose to introduce him to one of your roommates at the afterparty, but this does not affect his path.
He will blow you off after Initiation, but this does not affect his path.
If you're on his path, you will receive an apple pie from him on October 5th.
On October 30th, you'll receive a letter from Damien. The next night, you'll meet him before going to the Dark Dance. Choosing "No Way" ends Damien's path. Any other response will continue it.
On November 8th, Damien will invite you to dinner on the 9th if you're on his path, which you'll accept automatically. If you miss the date due to staying in with Ellen and Virginia, he'll show up on the 10th to reschedule for the 16th. Should you have detention that day because of the Donald Event, you can run to him and tell him you'll be late, which will cause him to reschedule one last time for the 23rd. If you miss THIS date because you're the treasurer and have to take part in the fundraiser, this breaks the path. Not running to him if you have detention will also break the path.
On December 8th, Damien will invite you to play Flowerstones. You can accept right away, or tell him you already promised Virginia you'd go to Sports Club with her, in which case you reschedule the Flowerstones game for the 13th. Either way, the path isn't broken.
You can think of Damien during the Holiday Blessing, but not doing so won't break the path.
On January 6th, Damien gives you a Christmas Present.
On January 14th, you'll see Pastel Rao hitting on Damien. His response depends on whether or not you're still on his path.
On January 24th, Damien confesses his love. You MUST answer "I'd love to" to stay on his path. Any other answer will break it.
Going on the date with Damien on the 25th will end up overriding and breaking any other dates you planned.
On February 1st, you find Damien and William arguing, and Damien invites you on a date that won't get interrupted.
Sending Damien a valentine won't affect the path, but you'll get cute or weird points depending on what kind of valentine you sent him.
On March 2nd, you go on a date to the lake with Damien. Here's where you get the kiss.
You wind up running to Damien after the fire event, but it turns out he wasn't the target.
On March 8th is the biggest event of Damien's path. He'll invite you to the gym and tell you he needs you to give him your soul so he won't die. Refusing ends the path. Accepting, but choosing "I hate you" ends the path. You must accept and say "I still love you" to stay on the path.
(Optional) During the Week of March 31st-April 4th, if you take Gym Class and have the spell Spirit Echoes, you can cast it to find out more of what happened that night.
On April 18th, you'll hear rumors that Damien has been seen.
On April 19th, you'll receive a letter from Damien. Destroying it ends the path. If you're in the Rose and Wasp, you can plot revenge against him, but this also ends the path. Choosing to wait continues the path.
On April 20th, you can go to meet Damien. Choosing "I feel nothing" ends the path. Any other option continues it.
On April 26th, Damien will send you a letter, asking to be your escort to the May Day Ball. At this point, there are two ways this can go. If you plead his case with Potsdam, she will reject your request, and your roommates will no longer speak to you until the Final Exam. If you turn down his request, this does not break the path.
During the Final Exam, if you made the plea with Potsdam, your roommates will demand that you make a solemn promise to never speak to Damien again. Refusing the demand will cause you to fail the Final Exam. Accepting the demand will allow you to continue the exam as normal, but with consequences for Damien's path later.
If you did not make the plea with Potsdam, on April 30th, you'll find a ring on your bed. You must put the ring on to complete Damien's path.
On the May Day Ball, things can play out several ways.
If you made the appeal to Potsdam...
...and did not make the promise to your friends, you slip away from the dance and meet Damien. However, you'll be transferred to Snake Hall, which will be reflected in your yearbook photo.
...and did make the promise to your friends, you'll slip away and meet Damien. If you choose "Run away," this breaks the path and you get a non-romantic yearbook page. If you choose "Greet Damien," you'll get the "Walking in Darkness" ending where you lose all your magic and Damien whisks you away.
If you did not make the appeal to Potsdam...
...and did not put the ring on, you will break Damien's path and go to the dance alone.
...and did put the ring on, you'll slip away from the dance and meet Damien.