Dragon fight.

Dragon should "climb" or perch on tower and with her breath reignite healing crystal, it would be slower process of her when she would sit on top and fire her breath to reignite crystal, if player hits her in the process she would stop and crystal would stay inactive. She would not attack player in the process.

It would be mostly punnishment that would let dragon heal little bit when player dies.

I would also make dragon to target player more often and shoot for him more often, also his breath should spread also vertically not only horizontal.

Dragon should also be more angry and powerful as her health gets lower, more targeting player and shooting for him.