This subclass gives the same martial prowess as the official Arcane knight, and Ebberon's Bone knight, but this time with a charismatic fey style magic. 

Spellcasting

When you reach 3rd level, you augment your martial prowess with the ability to cast spells. See Spells Rules for the general rules of spellcasting and the Spells Listing for the druid spell list.

Cantrips

You learn two cantrips of your choice from the druid spell list. You learn an additional druid cantrip of your choice at 10th level.

Spell Slots

The Rune Knight Spellcasting table shows how many spell slots you have to cast your druid spells of 1st level and higher. To cast one of these spells, you must expend a slot of the spell’s level or higher. You regain all expended spell slots when you finish a long rest.

For example, if you know the 1st-level spell ice knife and have a 1st-level and a 2nd-level spell slot available, you can cast ice knife using either slot.

Spells Known of 1st-Level and Higher

You know three 1st-level druid spells of your choice, two of which you must choose from the enchantment and conjuration spells on the druid spell list.

The Spells Known column of the Rune Knight Spellcasting table shows when you learn more druid spells of 1st level or higher. Each of these spells must be an enchantment or conjuration spell of your choice, and must be of a level for which you have spell slots. For instance, when you reach 7th level in this class, you can learn one new spell of 1st or 2nd level.

The spells you learn at 8th, 14th, and 20th level can come from any school of magic.

Whenever you gain a level in this class, you can replace one of the druid spells you know with another spell of your choice from the druid spell list. The new spell must be of a level for which you have spell slots, and it must be an enchantment or conjuration spell, unless you’re replacing the spell you gained at 3rd, 8th, 14th, or 20th level from any school of magic.

Spellcasting Ability

Charisma is your spellcasting ability for your druid spells, since you learn your spells through your emotions and connection to the feywild. You use your Charisma whenever a spell refers to your spellcasting ability. In addition, you use your Charisma modifier when setting the saving throw DC for a druid spell you cast and when making an attack roll with one.

Spell save DC = 8 + your proficiency bonus + your Charisma modifier

Spell attack modifier = your proficiency bonus + your Charisma modifier

Rune Knight Spellcasting

Fighter Level	Cantrips Known	Spells Known	— Spell Slots per Spell Level —
			1st	2nd	3rd	4th
3rd	2	3	2	—	—	—
4th	2	4	3	—	—	—
5th	2	4	3	—	—	—
6th	2	4	3	—	—	—
7th	2	5	4	2	—	—
8th	2	6	4	2	—	—
9th	2	6	4	2	—	—
10th	3	7	4	3	—	—
11th	3	8	4	3	—	—
12th	3	8	4	3	—	—
13th	3	9	4	3	2	—
14th	3	10	4	3	2	—
15th	3	10	4	3	2	—
16th	3	11	4	3	3	—
17th	3	11	4	3	3	—
18th	3	11	4	3	3	—
19th	3	12	4	3	3	1
20th	3	13	4	3	3	1

Weapon Rune

At 3rd level, you learn a ritual to create a magical rune on one weapon with the versatility property. You perform the ritual over the course of 1 hour, which can be done during a short rest. The weapon must be within your reach throughout the ritual, at the conclusion of which you touch the weapon and forge the rune.

Once completed, the weapon's material changes to a silver hue, with this rune burning into the edge of it, immediately after completing the ritual you can give that weapon a single one of the following properties until you take a long rest, or preform this ritual again; heavy, finesse, light, or reach.

You can have up to two weapons with a rune on them. If you attempt to add a rune to a third weapon, you must break a rune on one of the other two.

Trickester Magic

Beginning at 7th level, when you use your action to cast a spell, you use your bonus action to turn invisible until the start of your next turn.

Magical Resistance

At 10th level, you gain advantage on saving throws against spells and other magical effects.

Faerie's Escape

At 15th level, you gain the ability to teleport up to 30 feet to an unoccupied space you can see when you use your Action Surge. You can teleport before or after the additional action.

Improved Trickster Magic

Starting at 18th level, when you use your Trickster Magic feature, you leave an illusionary double of yourself in that spot. The double cannot move, but can make attacks of opportunity with your spell attack modifier.

It deals psychic damage equal to 1d8 + your charisma modifier. Once it makes this attack, it vanishes. The double has an AC equal to your spell DC, and if it is hit, immediately vanishes.

The illusion is hard to notice, but a successful intelligence (investigation) check (DC equal to your spell DC) reveals it to be an illusion.