Is this Love Triangle or 3P??? I won't mind some spoilers. LMK
Not really dude, most romance works with love triangles trope have a main character that's interested in two main leads. Ik the concept of a triangle is a polygon with three edges and all, but in fiction a love "triangle" is not usually that. Tho sometimes it is, and I wish it was more common, it's usually more interesting.
Honestly, it makes sense that Lucas is the end game.
He was always there for Athy. He always helped her with mana and taught her magic.
Had it been not him transporting Athy to Ijekiel as a fun they wouldn't have ever met until debutante.
He even told her about the World Tree Branch to save Claude. Although he didn't want to tell her this earlier for fear of losing her.
And even that prophecy Athy has where the whole nation is in ashes. And Lucas figures out that it might be because he will end up killing everyone until nothing but ashes are left in the nation if anything were to happen to Athy.
He is a mix of Tsundere and Yandere :3 but a great mc.
When a monster calls you a monster, you know that you are hella strong.