Crash Plains

You must keep concentration for the whole spell, or take 8d100 necrotic damage. If you roll below 400 damage, you must reroll it. If you can keep concentration for all 3 days, you can choose 2 plains of existence (astral, corrupted, mortal, creation, heavenly, and hellish) and combine them. All creatures in either plain must succeed on a dc 25 strength saving throw or take 6d6 bludgeoning damage and be knocked prone. A successful save means the creature takes half damage. After the two plains have crashed, all creatures from each plain must succeed on a dc 20 wisdom saving throw or have an irrisistable urge to fight the other plain's people. The sky turns red, and massive meteors with red fire randomly fall and strike the ground. Every other round, all creatures in innitiative must succeed on a dc 16 dexterity saving throw or take 8d8 bludgeoning damage, 16d4 thunder damage and be knocked prone. There are also large cracks inhe ground filled with crackling black energy. If you get knocked in, you take 16d8 radiant damage every turn you start in in and and are blinded until you get out of the crater. The two plains are combined until all creatures in both plains are dead, and the spell is reversed by someone sacrificing themselves by jumping into the largest black radiance crater that exists in the combination plain.