Dome of Defence

You have discovered a way to defend those outside of your care, protecting your friends from outside harm in many ways as a support.

As an action, you can summon a 20ft dome of shimmering translucent purple magic centered on you. When it is conjured into being, it has 6d8+twice your spellcasting modifier hp, resistance to force, lightning, thunder, and non-magical piercing damage. Whenever an attack would target you or any creature inside the bubble, it instead strikes the surface of the bubble. When it is destroyed, all creatures who were inside gain 1d8 temp hp and the spell ends. Friendly creatures can enter and exit the bubble at will, but hostile creatures must make a Wisdom save against your spell DC in order to enter the bubble. If the dome is targeted by a Disintegrate spell, it is automatically destroyed and the caster takes half of the spell's damage instead of the temp hp.

If cast as a reaction, you instead summon a semicircle of purple energy that is 10 ft tall and 10 ft in length, curving around you and above you within a 5 ft area around you. This shield will have half as many hp as the dome, if the shield is hit with a melee attack or non-magical ranged attack, it instead takes half the total damage it would take normally. Outside of that, it acts the same way as the dome.