Feedback on homebrew spell similar to Shadow Blade

I’m trying to create a homebrew spell that fills a similar niche to the Shadow Blade spell.

Goals:

  • Add meaningful decisions with significant tradeoffs, rather than raw strength. Using blade abilities leaves you without a weapon until your next turn, and costs your bonus to reform it.

  • Allow for highs and lows to combat through the ebb and flow of blade reforming. Costs a bonus action to use the abilities but also to reform blade, so only usable every other turn.

Sandstorm Blade

Level 4 transmutation

Components: S, M (a container of metallic sand worth 20G)

1 bonus action, 1 min duration, concentration

You form a shimmering blade of metallic sand in your hand. This magic sword lasts until the spell ends. It counts as a magical melee weapon with which you are proficient. It deals 3d8 slashing damage on a hit and has the finesse and light properties. If you drop the weapon or throw it, it dissipates at the end of the turn. Thereafter, while the spell persists, you can use a bonus action to cause the sword to reappear in your hand.

Additionally, on your turn when you strike a creature you can use your bonus action to change the sword:

  • Whirlwind. Your strike explodes the sword into a whirling cloud that surrounds you. Ranged attacks made against you have disadvantage until your next turn. Sword is lost until reformed.

  • Piercing strike. The blow strikes your target and onwards. If there is a creature directly behind your target you may strike them for 1d8 damage. Sword is lost until reformed.

  • Shredding edge. You send the sand coursing deep into the creature, tearing through it’s insides. Your blow explodes your sword, dealing an additional 1d8 damage. Sword is lost until reformed.

While you are wielding the sandstorm blade, you may spend your reaction to shape it to shield you from attacks, increasing your AC by 3 until your next turn. Sword is lost until reformed.

For context this is for use with a bladesinger.

Thank you!

Shadow Blade, Overchannel and Sneak Attack Dice

If a level 14 Evocation Wizard with 3 levels in Rogue, uses their Overchannel ability on a 5th level Shadow Blade spell and lands an attack against a creature dealing 4d8+Dexterity modifier + 2d6 sneak attack damage.

Because the Sneak Attack counts as “extra damage” (taking on all the damage properties that the Shadow Blade possesses) is it also maximized by Overchannel?

Does Overchannel even work on the Shadow Blade’s damage in the first place?

My first impression is yes to both of these but I might be overlooking something.

Do you take damage if you start your turn in the square of a blade barrier?

The spell blade barrier reads

If you evoke the barrier so that it appears where creatures are, each creature takes damage as if passing through the wall. Each such creature can avoid the wall (ending up on the side of its choice) and thus take no damage by making a successful Reflex save. (PHB p. 205)

In case a creature does not make the save, does it take damage for “passing” through the wall in it turrn?

Is it impossible to Ready a Green-Flame Blade?

I’ve noticed a curious quirk of wording when it comes to the Green-Flame Blade cantrip. Specifically, this tidbit:

As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell’s range, otherwise the spell fails.

Suppose I want to use my action to Ready a cast of Green-Flame Blade. The thing is, Readying a spell is described as casting it using your action, then holding it until you deliver it with your reaction. I haven’t struck an enemy with a melee attack as part of the casting so… does it fail, and thus prove itself impossible to Ready?

Does Green Flame Blade work if I’ve cast shillelegh on my staff

Shillelegh says that your attacks become magical but Green Flame Blade says it works with a melee attack.

As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell’s range, otherwise the spell fails.

Does the fact that my staffs attacks become magical stop Green Flame Blade from working?

Do natural weapon’s work with the Booming Blade spell?

As far as I can tell there are three different ways that “natural weapons” are described:

  • Aarakocra:

Talons: You are proficient with your unarmed strikes, which deal 1d4 slashing damage on a hit.

  • Tabaxi:

Cat’s Claws: In addition, your claws are natural weapons, which you can use to make unarmed strikes.

  • Centaur:

Hooves: Your hooves are natural melee weapons, which you can use to make unarmed strikes.

There also already exist the following two questions which explain that these wording differences do matter:

  • “Do natural melee weapons (from racial traits) trigger Improved Divine Smite?”
  • “What are natural weapons?”

How do these different classifications work with the booming blade spell, which states:

As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell’s range […]

Which races, if any, could use their unarmed strikes with booming blade?

Do opportunity attacks trigger booming blade? [duplicate]

This question already has an answer here:

  • Does Booming Blade trigger only when the creature moves locations? 1 answer

There have been some similar questions, such as here, but I was wondering if an opportunity attack triggers booming blade, for example (I will use mine) a dwarven cleric (he used magic initiate to get booming blade) hit a bugbear, and moved away. Would the bugbear take the booming blade effect damage when it does the opportunity attack?

Also, would you use strength as a modifier to hit with the melee weapon, or charisma since the melee attack is part of the spell? Thanks for your help!

Do opportunity attacks trigger booming blade? [duplicate]

This question already has an answer here:

  • Does Booming Blade trigger only when the creature moves locations? 1 answer

There have been some similar questions, such as here, but I was wondering if an opportunity attack triggers booming blade, for example (I will use mine) a dwarven cleric (he used magic initiate to get booming blade) hit a bugbear, and moved away. Would the bugbear take the booming blade effect damage when it does the opportunity attack?

Also, would you use strength as a modifier to hit with the melee weapon, or charisma since the melee attack is part of the spell? Thanks for your help!

Do opportunity attacks trigger booming blade? [duplicate]

This question already has an answer here:

  • Does Booming Blade trigger only when the creature moves locations? 1 answer

There have been some similar questions, such as here, but I was wondering if an opportunity attack triggers booming blade, for example (I will use mine) a dwarven cleric (he used magic initiate to get booming blade) hit a bugbear, and moved away. Would the bugbear take the booming blade effect damage when it does the opportunity attack?

Also, would you use strength as a modifier to hit with the melee weapon, or charisma since the melee attack is part of the spell? Thanks for your help!

Do opportunity attacks trigger booming blade? [duplicate]

This question already has an answer here:

  • Does Booming Blade trigger only when the creature moves locations? 1 answer

There have been some similar questions, such as here, but I was wondering if an opportunity attack triggers booming blade, for example (I will use mine) a dwarven cleric (he used magic initiate to get booming blade) hit a bugbear, and moved away. Would the bugbear take the booming blade effect damage when it does the opportunity attack?

Also, would you use strength as a modifier to hit with the melee weapon, or charisma since the melee attack is part of the spell? Thanks for your help!