Karsus' Dream (5e Equipment)

Staff, legendary (major tier) (requires attunement by a sorcerer or wizard with a 9th level spell slot)

In times long gone, magic was far from limited. Every person could learn cantrips easily, if they chose to, and there was no upper limit to the power a spell could achieve. History tends to repeat itself.

The staff itself has a half crystalline, half stone structure, but is as light as a feather. The smooth stone underneath is coated in almost completely opaque shards, like red and white stained glass. At the very top of the staff, a small perfectly spherical stone hovers, blood red.

Arcane Focus. You can use Karsus' Dream as an arcane focus.

Overcharge. When cast a spell using a 9th-level spell slot, you can expend one or more additional spell slots with a total level of 4 or greater to cast it at 10th level. When doing so, you scale the spell as if you had cast it at one level higher, but this also incurs additional effects. Choose two relevant spell modifiers from below. Once you have used this property of the staff, you can't use it again until the next dawn.

• Any creature damaged by this spell must make a Constitution saving throw against your spell save DC or be stunned for 1 minute.
• Any creature this effects or summons has their movement speeds increased by 15 feet and their AC increased by your spellcasting ability modifier (this cannot increase their AC above 22) until the spell ends.
• This spell can create creatures with a CR 2 higher than before. If these creatures were of a CR below 1, they are instead now CR 1.
• A creature damaged by this spell is knocked prone and pushed 20 feet away from you.
• Creatures can't have advantage on any saving throw made against this spell.
• If a creature does not have resistance or immunity against any damage the spell deals, it now has vulnerability to that damage.
• When choosing targets, this spell can target up to three additional targets of your choice.
• This spell can now target creatures as if they were not behind full cover.
• This spell now deals double damage to structures, or triple if it did already.
• You can change the duration by one step (1 minute into 10 minutes, 10 minutes to 1 hour, 1 hour into 8 hours, and so on). This cannot make instantaneous spells last 1 minute.
• This spell cannot damage or affect a friendly creature in any way.
• Instead of rolling for hit points healed, you instead heal the maximum value (for example, 1d6 becomes 6).
• A creature affected by this spell is poisoned until the spell ends or they make a successful save against it.
• This spell has a DC 30 instead of any other DC when another caster attempts to end it (for instance, via counterspell).
• A creature affected or summoned by this spell can make an additional weapon attack as a bonus action if they couldn't already until the spell ends.