Bestow Greater Curse

You point at a creature within range and speak a fell curse, binding them to its conditions. You must bind a prepared spell of 3rd level or lower to your curse, and your curse must include a condition that will cause the bound spell to trigger. Whenever the stated condition of the curse is met the bound spell is automatically cast, treating the creature who triggered it as the target and/or origin of the spell.

Casting the spell takes 2 rounds or the normal casting time of the bound spell, whichever is longer. If the bound spell requires material components, you must be carrying those components (or an Arcane Focus if they lack a gold cost), and they are consumed if the spell would normally consume them. If the target considers your curse to be desirable at the time of casting, the spell fails. 

If the spell requires concentration, the curse-bound version does not. However you cannot take actions to influence a curse-bound spell. 

For example, you might utter the curse “Until the day you kiss 5 frogs, steel will be your enemy for even the slightest touch will shock you with lightning!”, binding the spell Witch Bolt to it. Because you cannot take a bonus action to maintain the spell’s effects, the target will only take the initial damage when the spell is cast.

You can only directly target creatures that can hear your words (though they need not understand you), however your curse can target other creatures via some kind of relationship with the target (for example by saying “you and all your descendants”). The condition of the spell must also be something the creature can realistically avoid. If the DM thinks your curse is too hard to avoid or targets too large a group, they might ask you to change your wording.

If the wording of your curse is in any way unclear, your words must be interpreted by your DM, which could cause the curse to act in unexpected ways. For example, you might bestow the curse “If you or any of your friends enter my home ever again, you will run away in terror!” and bind the spell Command to it. 

Because what qualifies as a “friend” is unclear, the curse might trigger for anyone the target has ever called “friend” regardless of their actual relationship; and because of the unclear definition of “home” the curse may or may not follow you if you move away. 

The power of the curse is fueled by your own spellcasting abilities. Any time the bound spell triggers, your magic is expended according to these rules:

• Whenever possible, expend a spell slot equal to the level of the bound spell.

• If you have no spell slots of equal level, expend a spell slot of higher level then the bound spell (this doesn’t give the spell any extra benefits)

• If you have no spell slots of equal or higher level, expend all of your spell slots.

• If you have no spell slots, you lose the ability to cast cantrips until your next Long Rest.

• If you have no cantrips you can cast, the bound spell fails to trigger.

If you die, the spell is fueled by your spirit and continues to function without expending spell slots. If you return to life, the curse continues as normal.