Domain Expansion

In order to cast domain expansion, the caster must make a specific hand gesture while saying "domain expansion: (followed by a prepared spell the caster would wish to use) then the spell will be cast, affecting any targeted creatures. When cast, a large sphere is placed around the user and one or more targeted enemies. the sphere is made of a very strong material which requires a strength check (DC18) to break through. when inside the cursed domain, the interior will resemble characteristics of the spell chosen (the specifics of this are chosen by the caster). when inside the domain, the caster may use the selected spell as a cantrip while retaining the original properties of the spell at the level originally selected. the caster does not need to roll to hit for the selected spell as every time it is cast will be an automatic crit.  these properties only affect the caster, any other creatures inside the domain will have disadvantage on attack rolls. the spell ends when either; the caster chooses to end the spell, or the domain is broken into or out of.