Elemental Enchanter

My intention with this subclass is to make a damage dealer with a little support and utility.

Enchanted Weapon

At 3rd level, you gain the ability to elementally enchant weapons. As a bonus action,  a nonmagical weapon you touch is imbued with an element. You expend an enchantment point to do this. You may also sacrifice the use of your second wind to perform two enchantments in one turn. Choose one of the following damage types: acid, cold, fire, force, lightning, thunder, radiant (18th level), or necrotic (18th level). A weapon may only have one enchantment at a time. 

The enchantment lasts 5 minutes and adds a 1d6 damage of the chosen element to your weapon attacks. The damage increases as you reach 5th level (2d6), 7th level (2d8), 11th level (3d8), 15th level (4d8), 18th level (5d10).

You have enchantment points equivalent to 1 plus your proficiency bonus. You regain your enchantment points on a long rest.

Enchanter’s Attunement

At 7th level, you may now enchant all nonmagical objects along with weapons at the cost of enchantment points. As a bonus action, you may grant armor or accessories to have resistance to a chosen element. Choose one of the following damage types: acid, cold, fire, force, lightning, thunder, radiant (18th level), necrotic (18th level). The enchantment lasts for 5 minutes. Only one resistance can be applied at a time. 

Enchanting objects can also create a secondary effect. The enchanter can choose if the secondary effects occur or not. This must be decided at the moment of enchantment. The enchantment lasts 24 hours for every enchantment point used. The secondary effects are as follows.

Acid: The object will disintegrate at the end of its enchantment period.

Cold: The object will freeze or be frigid.

Fire: The object is now scalding. 

Force: Anything that makes contact with the object is sent flying back 20 feet. (If the enchanter attempts to enchant their weapon with this effect then they also will be flung away from their own weapon.)

Lightning: The object will glow a pale blue as if lighting.

Thunder: Touching the object will create a sound that emulates thunder.

Radiant: The object stops chaotic aligned creatures that see the object from lying. (18th level).

Necrotic: The object frightens lawful aligned creatures for a minute. (18th level).

Elemental Burst

At 11th level, as a bonus action you may make an object that you touch explode with elemental energy. The explosion occurs at your command, but must be within sight. Choose one of the following damage types: acid, cold, fire, force, lightning, thunder, radiant (18th level), or necrotic (18th level). Each creature in a 10-foot-radius sphere centered on the object, except for you, must make a Dexterity saving throw. Any creature in the radius takes 4d6 of the chosen damage on a failed save, or half as much damage on a successful one. This cost an enchantment point. 

The damage increases as you reach 15th level (8d6), 18th level (10d6).

Magical Mark

At 15th level, you may sacrifice the use of your action surge to mark a creature and make them vulnerable to a single damage type. Choose one of the following damage types: acid, cold, fire, force, lightning, thunder, radiant (18th level), necrotic (18th level). The vulnerability lasts until the affected creature’s next turn.

Mastery of the Elements

At 18th level your mastery over elements has reached its peak. You may now enchant a nonmagical weapon, armor, and accessories with two elements. Magical weapons may also be enchanted, but only with a single element. Choose one of the following damage types: acid, cold, fire, force, lightning, thunder, radiant, or necrotic.