Planning new au!!! Underspell :v welp... what did you think? Should I continue or leave this plan?

In this au.. all depends on magic...and all life from magic.. Sans have an ice magic...
But someday when Sans take a walk to the forgotten path where forbidden to pass (because he bored) he found a girl who traped in ice and instantly fall in love with her.. but strangely even if he have the strongest ice magic in underground.. he can't melt or break the ice...
He finally decided to ask Dr alphys and she said the ice is only can be break from inside and the girl magic is to weak to do it... so Sans come everyday to share his magic... but after she come out Sans found out she have a fire magic

Can fire and ice become one?

And why she are trapped in ice in first place?

Hahahhahahahhahahahahaa okay my imagination is to strong XD gosh...
Why I decide to stop making melodieatale? Because I notice that I don't know anything about music and notes so it's troublesome...
And for my kouhai trickster-_- I'm sorry I can't make your request now... maybe I will do it after my exams is over 😭😭😭I'm sorryyyyy😭😭😭