D&D Spells for Heroes of Might and Magic

For the past two and a half years, I've been collecting ideas for 5e magic items and spells based on games and other franchises I'm familiar with. Last week, I decided to finally compile all the spells for one of the franchises, Heroes of Might and Magic, into an actual document that could be sold on DMsGuild or something. I'd love any feedback you have on balance.

My main goal when making this document, and in adapting spells from other sources in general, is to merge the franchise with D&D as seamlessly as possible. I take great care to look at other existing spells, to follow the tips for designing spells in the DMG, and to even do things like tweak the wording slightly in order to make it sound more like a spell that would be in an official D&D source. I also try to make the spells versatile enough and vague enough that each would fit into any D&D campaign setting, not only the one the spell came from.

Lots of franchises have spells that are more or less the same as D&D, such as fireball, cone of cold, and heal, so for these I just skip entirely and focus more on ones that would be a welcome, fresh addition to the game. In other cases, in the case of clone in Heroes of Might and Magic III, I change the name so that it's clear that it does something different than the existing spell in D&D that had the same name. Lastly, if a spell's name doesn't make sense given what it does in the original game, I use the name as inspiration for a brand new spell. For instance, in Heroes 3, a spell called forgetfulness causes half of all creatures you target to "forget" to use their ranged attack on their turn. Instead, I just made it a spell similar to modify memory, though not as potent.

Below are some of my favorite spells I adapted from Heroes of Might and Magic II and III:

Magic Arrow

1st-level evocation
Casting Time: 1 action
Range: 120 feet
Components: V, S
Duration: Instantaneous
 
An arrow of magical energy flies from your hand toward a target in range. Make a ranged spell attack. On a hit, the target takes 2d10 force damage.
     At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d10 for each slot level above 1st.

Counterstrike

3rd-level enchantment
Casting Time: 1 action
Range: 60 feet
Components: V, S
Duration: 1 minute (concentration)
 
You grant a creature within range the ability to counter incoming attacks. For the duration, the creature can use its reaction when it takes damage from a creature within 5 feet of it to make one melee weapon attack against that creature.

Magic Mirror

4th-level abjuration
Casting Time: 1 action
Range: Touch
Components: V, S, M (a small jeweled mirror worth at least 100 gp)
Duration: 1 minute (concentration)
 
A creature you touch reflects magic for the duration. Any time the affected creature is targeted by a spell of 4th level or lower that affects only it or that is a line spell, that creature can roll a d4. On a 1 or 2, the creature is affected by the spell but has resistance to any damage it causes. On a roll of 3 or 4, the creature is unaffected, and the effect is reflected back at the caster as though it originated from the creature, turning the caster into a target.
     At Higher Levels. When you cast this spell using a spell slot of a higher level, the level of spell this it can reflect is equal to the spell level cast.

Slayer

5th-level transmutation
Casting Time: 1 bonus action
Range: Touch
Components: V, S
Duration: 1 minute (concentration)
 
You touch a willing creature. For the duration, that creature deals an additional 3d6 damage on weapon hits against the creatures of the following types: aberrations, celestials, dragons, fiends, and giants.

Summon Boat

6th-level conjuration
Casting Time: 1 minute
Range: 120 feet
Components: V, S, M (a pearl worth at least 300 gp, which the spell consumes)
Duration: 24 hours
 
A wooden boat emerges from a body of water within range that is at least 120 feet square. Any creatures in the ship's space when it is summoned are harmlessly lifted as the ship rises.
     The boat uses the statistics of a keelboat (see Ghosts of Saltmarsh). It is 60 feet by 20 feet in size and can hold up to 7 passengers comfortably. It has 100 hit points, 15 AC, a damage threshold of 10, and a sailing speed of 3 miles per hour. You are considered proficient with the vehicle and with navigator's tools while on the boat. The ship is furnished with cots, rope, and all the tools necessary for maintenance and sailing, as well as 1 days' worth of rations. The boat is decorated however you like. If anything created by this spell is taken off of the boat, it transforms to salt water and disappears.
     After 24 hours or when you cast this spell to summon a different boat, the boat harmlessly fades out of existence, unless you cast the spell again.
     If you cast this spell every day for 10 days, the boat and all its cargo become permanent.

Click here to see the document in its entirety on the Homebrewery!