Domain Opening: Magical Instability

As the words "Domain Opening: Magical Instability" a Shadow sphere in a 120 foot radius is created trapping those in the radius in it wherever the summoner can see. The sphere has 25 hit points (scales up when hitting level 10) when the domain reaches 0 or the timer of 5 minutes runs out it is shattered into glass like pieces that fade away after a few seconds. Inside the domain the caster gains an unstable amount of magical energy allowing the use of all prepared and learned spells along with the ability to negate all armor of those trapped in the domain. After the domain is either destroyed or dispelled by timer running out the casters loses their  unlimited use of prepared and learned spells and the armor negation. The caster also losses all spells slots and requires a long rest to cast spells again including cantrips.