Can a Shadow Magic sorcerer cast the Darkness spell using sorcery points, and still apply a Metamagic option to it?

Question

Let's say that I want to use the Shadow Magic sorcerer feature Eyes of the Dark (XGtE, p. 51) to cast the darkness spell by spending 2 sorcery points. More, I would like to cast it as a bonus action, using the Metamagic option Quickened Spell.

Is this possible? Can a Shadow Magic sorcerer cast the darkness spell using sorcery points, and still apply a Metamagic option to it?

The intended final result would be that the sorcerer casts darkness as a bonus action, using 4 sorcery points and no spell slot.

Answer 1

Yes, Metamagic may be applied to spells that are cast using a class feature instead of spell slots.

The Metamagic feature says a metamagic option may be applied when the sorcerer casts a spell:

You can use only one Metamagic option on a spell when you cast it, unless otherwise noted.

That is the only criteria: the Sorcerer must cast the spell.

Metamagic would not apply if the spell's effect were applied without being cast. For example, some potions (e.g. the potion of clairvoyance, potion of diminution, and potion of gaseous form, to name a few) say things like "gain the effect of" a spell. In such instances, no spell is actually cast, and so Metamagic could not be applied.

Then we refer to the Shadow Magic sorcerer's Eyes of the Dark feature (XGtE, p. 51):

[...] you learn the darkness spell [...]. In addition, you can cast it by spending 2 sorcery points or by expending a spell slot. If you cast it with sorcery points, you can see through the darkness created by the spell.

This tells us that the Sorcerer is casting the spell. This satisfies the criteria as laid out above. As a result, the Shadow Sorcerer may cast darkness for 2 sorcery points and then apply any relevant Metamagic option of their choice for its corresponding additional sorcery point cost to that spell.

In your case, that means a quickened Eyes of the Dark darkness spell would cost 4 sorcery points (and not cost a spell slot), as you say.

Answer 2

Yes, you should be able to quicken a darkness spell cast in this way.

I'm assuming you're concerned about this restriction from the description of the Metamagic feature of the Sorcerer class:

You can use only one Metamagic option on a spell when you cast it, unless otherwise noted.

Metamagic options are sub-abilities granted by the Metamagic class feature, including Quickened Spell.

In contrast, the Shadow Magic sorcerer's Eyes of the Dark feature states (XGtE, p. 51):

When you reach 3rd level in this class, you learn the darkness spell, which doesn't count against your number of sorcerer spells known. In addition, you can cast it by spending 2 sorcery points or by expending a spell slot. If you cast it with sorcery points, you can see through the darkness created by the spell.

Eyes of the Dark makes no mention of this being a Metamagic option; it is just a class feature that gives you an additional way to use your sorcery points. So yes, you should be able to quicken the spell if you cast it this way.

Answer 3

No rule is violated in this process:

You are casting a spell [Darkness] per the ability description. (Allowed) You are applying a single metamagic option [Quickened Spell] to the spell. (Allowed)

Casting the spell with sorcery points is still casting the spell, there isn't a source restriction on how a spell is cast, so combining the two works as normal.