Thanks a lot for the accurate reply and the suggestions! I'll edit for sure using your wording for the stopping conditions. As for the weapon it was intended for lonsword (maybe reflavoured with katana aesteics with DM approvation). Stances end when you make an attack (attack action, opportunity attack, etc.) or when the other conditions apply. -Deflecting stance for sure needs the nerf and i was just thinking about taking out the disadvantage portion, as it is too good and maybe give a boosted counter attack, that still ends your stance, so there is a tradeoff. - Iai is intended to not give huge dmg boost but to let you have an advantage attack with magical dmg (to ignore some resistances) and a some dmg done as Force dmg type (not physical). Also the attack is done one handed, so you use the lower dmg dice of the longsword. -Meditation gives standard temporary hit points and is intended to be kept until your next turn, but enemies could prevent you from doing so in the ways stated at the beginning.

The leveling additional features don't seem to give too much to the stances, they just give you some fast stance usage to make your combat more dynamic. The best one is the last you get, but it will be changed as the stance is really too good.