[quote=@TheHangedMan]
<Snipped quote>

Why was Piper fighting in an abandoned room (alone apparently) and why was Jax going there :hmm
[/quote]

Piper just went like "gotta practise this new very destructive spell i learned" and Jax showed up like "wait this room isnt abandoned this is the ravenclaw commonroom-" jk jk, Daydreamz explained it well xD
Piper was probably practising spells since she tends to learn even more advanced stuff by herself (and luckily her wand material only supports it), for example a patroun or other stuff above her year level