DayStar

The caster charges up magical energy. Only focusing on two things, and blocking the rest of the world out. An aura of building power and pressure surrounds the caster, as bright light emanates from above. Until the caster's next turn, if at night or indoors, the level of light counts as clear mid-day for several miles. Applying any negative effects of light to creatures and players. 

 If the next turn comes without being attacked, nothing happens and the spell is lost. However, if the caster is attacked, they magically avoid the attack with unnatural precision and speed.  Followed by finishing a celestial chant with "My mother is the Star of Morning, the child of dawn. The star thrown to the Earth shall obtain victory! - A dazzling star falls into hell!"

Following that, a massive, brightly burning blue star comes slamming down, onto the attacker, engulfing them in heat and light. Dealing 9d6 Radiant and 9d6 fire damage. Anyone within 20 feet of the attacker, needs to roll a dexterity Save. When using their reaction to avoid taking damage, the caster will only fail if the Attack roll is a natural 20. 

Getting hit will disrupt the spell, If the spell isn't disrupted, and there are multiple attackers. The evasion still comes into play until the next round, where Daystar hits the first attacker.