Need some help balancing spells

So I’m making a custom setting for my players and have been working on it for years. And as with many other custom settings there are a few Homebrew spells the players can take a use which are part of the world. Thing is I’m good at fun concepts. Not really with balance. So I was going to put the spells I have here along with the concept behind them and want your help actually making them balanced in any way. And please be nice with your criticism if that’s ok

Spells

Level 2

Nightmare

Spell lists: wizard, warlock, sorcerer, cleric, Druid

Range: Touch (1 foot)

Casting time: Action

School: Illusion

Components: S

Duration: concentration up to 1 minute

Description: you touch the body of a sleeping creature and enter their dream as a nightmarish monster. You are both transported to a 60 foot by 60 foot dream realm and your body goes unconscious.

You and creature retain all of your abilities aside from spells though cannot deal damage to eachother in the dream realm.

If you manage to touch the creature inside the dream realm the spell ends and the creature takes 5d12 psychic damage if this damage kills the creature its body simply dies with no obvious signs of damage.

Upcasting: when casted at a higher level its damage increases by 2d12 for each spell level

Concept: meant to be a greedy Krueger esc spell which deals massive damage but is incredibly hard to actually get damage out of. Also intended for assassins

Kalabazan’s Circle of weavelight

Spell lists: wizard, bard, sorcerer

Range: 10 feet

Casting time: Action

School: conjuration

Components: V,S

Duration: concentration up to 1 minute

Description: you conjure a circle of runes and sigils 4 squares in diameter. any creature inside that circle gains a +2 to their spell attack rolls and +1 to their spell save Dc

If they leave the circle the effect ends immediately

The caster can use their action on subsequent turns to move the circle up to 20 feet

Upcasting: The bonus to a creatures spell save Dc increases for every 2 additional levels this spell is cast at and the bonus to attack rolls increases by 1 for every level this spell is upcast

Concept: based terra magicka and its concept of a very small area the player has to stay inside in order to receive the benefit but the benefit being very well worth it.

Level 3

Ricochet shot

Spell lists: wizard, sorcerer, bard, warlock,

Range: 60 feet

Casting time: Action

School: evocation

Components: V,S

Duration: instantaneous

Description: you fire a ball or glowing light towards a creature or object within range. Make a spell attack roll. If you hit it deals 2d8 force damage. And you can fire the spell again from the object or creature hit. It can ricochet this way up to 2 times

Upcasting: when you cast this spell at a higher level. The amount of ricochets it can preform increases by 1 for each additional level.

Concept: Really meant to to the spell version of that cartoon trope of a ball that constantly bounces around hitting everyone.

Level 4

Swampmothers kiss

Spell lists: wizard, cleric, warlock, Druid

Casting time: action

Range: (self)

School: evocation

Components: S M (an onion)

Duration: concentration up to 1 minute

Description: You blow a kiss in a direction of your choosing and a cloud insects and glowing swamp fumes is expelled from your mouth.

This cloud occupies a 5 foot cube and moves along any path up to 50 feet.

Up to 4 creatures that it moves through receive the swamps curse indicated by a sickly green glow and insects swarming around them.

On this turn and subsequent turns the caster can use their bonus action to invoke the swamps curse on a creature that has it. The creature must make a charisma save or take 3d8 acid damage and receive a level of exhaustion.

Once the curse is invoked the curse is removed from that creature.

Upcasting: when casted at a higher level. The number of targets increases by 1 and it deals an additional d8 acid damage when invoked

Concept: meant to be a gross swampy spell with the idea of a cloud flying around infecting creatures before the caster snaps their fingers an each creature infected begins melting.

Also mean to give acid damage a viable late game spell.

Level 5

Crescendo

Spell lists: wizard, bard, cleric

Casting time: action

Range: (self)

School: evocation

Components: V

Duration: (concentration up to 3 rounds)

Description: you sing a glorious melody laden with magic.

The melody blasts a 30 foot cone in front of you. All creatures inside must make a wisdom save against your spell save dc or take 4d8 thunder damage

After casting the spell on your following turn you can use your action to preform your second crescendo which creates a 40 foot cone in front of you. All creatures inside must make a wisdom save against your spell save Dc or take 5d8 thunder damage

On the turn after casting your second crescendo you can use your action to cast your final crescendo a golden blast of sonic energy fires in a 60 foot cone in front of you. All creatures inside must make a wisdom save against your spell save dc or take 6d8 thunder damage and 2d10 radiant damage

Upcasting: when cast at a higher level the amount of radiant damage your final crescendo deals increases by 1d10

Concept: Meant to give thunder damage a late game representation. The idea being that the player is casting this spell fully intending to push it to that final crescendo and if they manage to make it that’s when the spell really deals its damage. And thus interrupting the spell is very easy.

Level 6

Song of spirits

Spell lists: bard, cleric, warlock

Range: 120 feet

Casting time: Action

School: necromancy

Components: V S M (corpses of a small medium or large creature which the spell destroys)

Duration: 1 hour

Description: You play a horrible melody that rips a tear into the afterlife causing spirits of the undead to emerge from any nearby corpse.

You summon undead from up to 4 Corpses disintegrating those corpses in the process. within the spells range. These undead have a ghostly almost ethereal aspect to them regardless of type

The combined Cr of these monsters can be up to 14 or lower

These monsters will retain their exact stat block though will attack any creature on the battlefield indiscriminately.

Upcasting: for each additional level the maximum cr increases by 2 and the total amount of corpses that can be targeted increases by 1

Concept: meant to be a “welp F&@k it we’re opening Pandora’s box” type of spell. Summoning a bunch of powerful monsters the caster has zero control over.