Arcane elementling

Magic resistance: The Arcane elementling has advantage on saving throws and ability checks related to a spell in any way.

Innate Spellcasting. The Arcane elementling is a 6th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 15, +4 to hit with spell attacks). The Arcane elementling has 15 charges available and can use some to cast a spell, depending on the spell level. It can cast any spell of the specified level without components. Some of its actions use charges as well. 

Cantrips: no charge, cast as if the elemental were 13th level

1st or 2nd level: 1 charge

Limited telepathy: The arcane elementling can communicate simple thoughts, emotions, or ideas to any creature within 30 feet of it. The creatures in the area can communicate simple thoughts, emotions, or ideas to the elementling, but if the creatures communicate anything more, than the elementling receives the simplest form of the communicated thought

Arcane casting (3 spellcasting charges). The Arcane elemental uses one of the following abilities:

• Earthen instability: In a 10-foot radius centered on the elememtling, the ground is difficult terrain.
• Call blaze: The elementling chooses a point within 30 feet of it. For the next round, in a 5-foot radius sphere centered on that point, any creatures who start their turns in that area must make a DC 14 dexterity save or take 9 (1d8+5) fire damage
• Wind sweep: In a 10-foot radius centered on the elementling, all creatures must make a DC 14 strength check or move 10 feet away from the elementling and be knocked prone
• Water bolt: The elementling makes a ranged spell attack (+4 to hit) against a target within 20 feet of it. On a hit, the target is moved 10 feet away from the elementling, knocked prone, and restrained until the end of the round.

Arcane Strike. Melee Weapon Attack: +4 to hit, reach 5 ft., 1 target. Hit: 13 (1d12 + 7) Force damage. 

Arcane bolt. Ranged Weapon Attack: +4 to hit, range 40/100 ft., 1 target. Hit:8 (1d8 + 4) Force damage.

Spell reflection (recharge 5/6): The Arcane elemental, in reaction to a 3rd-level or lower spell with the Arcane elemental as the target or with the Arcane elemental in the area of effect, casts the same spell with the lowest level possible back at the caster, the caster being the target or the area of effect centered on the caster.