If a spell is twinned, does the caster need to provide costly material components for each target?

The Divine Soul Sorcerer can gain access to the revivify spell pretty easily (along with other costly resurrection spells), which has a costly material component that the spell consumes (300 gp worth of diamonds).

If after a particularly rough battle, can the Sorcerer use revivify on two separate creatures who have died for the cost of just 300 gp worth of diamonds or would it require 600 gp worth?

For the sake of this question, assume that a dead creature is a creature and not an object. If it helps, you could consider the stoneskin spell as well.

Can you use twinned spell on the same target?

So me and my DM have been arguing on how Twinned spell works.

Twinned spell:

When you cast a spell that targets only one creature and doesn’t have a range of self, you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell (1 sorcery point if the spell is a cantrip).

I argued that "a second creature" can be a the same target as it is not worded as "another creature"

For this example counter spell with twinned spell.

A wizard casts fireball on me

I use CounterSpell#1 with Twinned Spell

Wizard casts CounterSpell on my CounterSpell#1 I use him as the same

target for my twinned Spell CounterSpell#2

Result countered

Is this possible?

Can the spell Booming Blade be affected by the Twinned Spell metamagic?

Booming blade is a Sword Coast Adventurer’s Guide cantrip that allows the spellcaster to make a melee weapon attack with their weapon and add additional power to the attack:

You brandish the weapon used in the spell’s casting and make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapon attack’s normal effects and then becomes sheathed in booming energy until the start of your next turn. If the target willingly moves 5 feet or more before then, the target takes 1d8 thunder damage, and the spell ends

Booming Blade, Sword Coast Adventurer’s Guide, pg. 142

The Twinned Spell metamagic permits a Sorcerer to take any spell that targets only a single creature, and cast it twice, targeting a different creature.

When you cast a spell that targets only one creature and doesn’t have a range of self, you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell (1 sorcery point if the spell is a cantrip).

To be eligible, a spell must be incapable of targeting more than one creature at the spell’s current level. For example, magic missile and scorching ray aren’t eligible, but ray of frost and chromatic orb are.

Twinned Spell, Player’s Handbook, pg. 102

It has been commonly accepted that this is a valid use of this metamagic/cantrip combo, but a recent Errata to the spell has changed its range to "Self (5-foot radius)". Is this spell still eligible to be Twinned?

If one target of a Twinned Spell has 0 HP, does the Grave cleric’s Circle of Mortality feature maximize healing on a second target who’s not at 0 HP?

One PC is a multiclassed Grave Domain cleric/sorcerer. They cast a healing spell on a PC that has 0 health, and use the Twinned Spell Metamagic option to target another PC with the same spell.

Would the second PC also have its healing from the spell maximized by the Grave cleric’s Circle of Mortality feature (XGtE, p. 20), even if the second PC is not also at 0 HP?

Illusionist Bracers and Twinned spell as a bonus action

Illusionist Bracers (GGR, page 178) Says:

While wearing the bracers, whenever you cast a cantrip, you can use a bonus action on the same turn to cast that cantrip a second time.

Twinned Spell (PHB, page 102) Says:

When you Cast a Spell that Targets only one creature and doesn’t have a range of self, you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell (1 sorcery point if the spell is a cantrip)

Can I Twin cast Booming Blade (SCAG, page 142) as an action and using the Illusionist bracers, twin cast it again as a bonus action? Thus attacking the same 4 targets twice each?

If I twinned spell cast Glyph of Warding as a spell glyph, can I store two different spells, or does it need to be the same one?

I have a sorcerer wizard. He wants to use twinned spell metamagic to cast glyph of warding as a spell glygh, twice on two different surfaces.

Spell Glyph. You can store a prepared spell of 3rd level or lower in the glyph by casting it as part of creating the glyph.

Can he cast two different spells to be stored in the spell glyph, or would it be the same spell twice?

Can the sorcerer’s Twinned Spell metamagic and the Enchantment wizard’s Split Enchantment feature be used at the same time?

The Twinned Spell option for the sorcerer’s Metamagic feature says (PHB, p. 102):

When you cast a spell that targets only one creature and doesn’t have a range of self, you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell (1 sorcery point if the spell is a cantrip).

To be eligible, a spell must be incapable of targeting more than one creature at the spell’s current level. For example, magic missile and scorching ray aren’t eligible, but ray of frost and chromatic orb are.

Similarly, the School of Enchantment wizard’s Split Enchantment feature says (PHB, p. 117):

Starting at 10th level, when you cast an enchantment spell of 1st level or higher that targets only one creature, you can have it target a second creature.

If a character with access to both Twinned Spell and Split Enchantment casts a spell that fulfills the requirements for both, can both features be used at the same time?

Does the Tempest domain’s Destructive Wrath maximize ongoing damage from a twinned Witch Bolt?

I have a multiclass tempest cleric/sorcerer.

If I twin Witch Bolt and then use Channel Divinity: Destructive Wrath, which allows me to deal max thunder or lightning damage, are both bolts impacted? I assume I can concentrate on both because it is one spell casting but is the lingering effect of witch bolt also maximized?

Can I Quicken a cantrip to cast it twice in a turn and also use Twinned Spell on both castings?

I’m currently building a monk sorcerer who uses melee spell attacks, notably the cantrip Shocking Grasp. Can I use the Quickened Spell Metamagic option to cast the spell as a bonus action and then use the Twinned Spell Metamagic option to attack an additional enemy, then use Shocking Grasp again as my action and use Twinned Spell again to attack both enemies a second time?

Can crown of madness be twinned?

I’m looking to build a sorcerer focused on the twinned spell metamagic and which spells I can use with it (Haste!! :). Looking around I came across these tweets from Jeremy Crawford stating that Dragon’s Breath cannot be twinned. From my understanding, this is because the effects of it can damage multiple people. Contrary to spells like haste, which can also damage multiple targets with the extra attack, this spell explicitly states the second set of targets. The spell reads:

Until the spell ends, the creature can use an action to exhale energy of the chosen type in a 15-foot cone. Each creature in that area must make a Dexterity saving throw, taking 3d6 damage of the chosen type on a failed save, or half as much damage on a successful one.

So I was wondering what other spells on my list are affected by this and I came across Crown of madness, which states the following:

The charmed target must use its action before moving on each of its turns to make a melee attack against a creature other than itself that you mentally choose.

So this spell also has a second set of targets explicit in its description. This led me to this question:

Can Crown of Madness be twinned?

Note: While researching this, I found this similar question on RPG.SE, which is about the spell Enemies Abound. I think this is different, because in Crown of Madness the spell caster himself chooses the other creature that is damaged. So more of a direct target of the spell than in Enemies Abound which simply makes the creature perceive more enemies. So I do think this is not a duplicate.