Desire

Desire is the mightiest spell a mortal creature can cast. By simply thinking, you can alter the very foundations of reality in accord with your desires.

The basic use of this spell is to duplicate any other spell of 9th level or lower. You don't need to meet any requirements in that spell, including costly components. The spell simply takes effect.

Alternatively, you can create one of the following effects of your choice:

• You create one object of up to 250,000,000 gp in value. The object appears in an unoccupied space you can see on the ground.
• You allow up to twenty creatures that you can see to regain all hit points, and you end all effects on them.
• You grant up to ten creatures that you can see immunity to all damage.
• You grant up to ten creatures you can see immunity to a single spell or other magical effect for 8 hours. For instance, you could make yourself and all your companions immune to a lich's life drain attack.
• You undo a single recent event by forcing a reroll of any roll made within the last round (including your last turn). Reality reshapes itself to accommodate the new result. For example, a Desire spell could undo an opponent's successful save, a foe's critical hit, or a friend's failed save. You can force the reroll to be made with advantage or disadvantage, and you can choose whether to use the reroll or the original roll.

 
You might be able to achieve something beyond the scope of the above examples. State your wish to the DM as precisely as possible. Literally ANYTHING can happen with no negative consequenses!!!!