so,the horn of trixie it’s like that because her daughter starry sky was take by the past of her mothers,the demon and the alicorn amulet and trixie make a sacrifice arrested demon starry  
to the alicorn amulet,iridessa gets really bad with her mom but some years ago trixie decide to release starry and some weeks then this happened.
 
sunset-hi,honey
 
trixie-hi,love
 
trixie and sunset kissed
 
sunset-so,what you are doing here?
 
trixie-well,like to see the moon when she rise
 
sunset-but she rise like a long time
 
trixie-i know,it’s really gold in here i like
 
sunset-you are strange
 
trixie-but even i am strange you marry me
 
sunset-hey,look your horn see better
 
trixie-really?cool!
 
sunset-i think its because you release starry
 
trixie-yeah,maybe
 
trixie and sunset look at they eyes