Wuthering Myrmidon

Amphibious. The Myrmidon can breathe air and water

Armoured. Conjuring a Wuthering Myrmidon binds it to whatever armour was used for it. If the armour requires Attunement, then the creature that conjure the Myrmidon must also Attune to the armour, if they are not already (it can without having to wear the armour). It otherwise gains all benefits of the armour

Watery Wave. The Myrmidon has a copy of the Wuthering Wave, whatever the weapon may be. The copy does not have the Convene Feature. It is made out of water, and it is Proficient in it. It can also use any Mastery Property that the weapon has. It can not part with it's copy, whether willingly or forcefully, therefore it can not throw the weapon

Multiattack. The Myrmidon makes two Wuther attacks.

Wuthering Wave. The Myrmidon attacks with its copy of Wuthering Wave. It makes an attack roll with the weapon's properties. Its to hit would be +14 for Strength or +11 for Dexterity, depending on the weapon. On a hit, it deals the weapon's damage plus its Strength or Dexterity modifier, also depending on the weapon

Freezing Strikes (Recharge 6). The Myrmidon uses Multiattack. Each attack that hits deals an extra 5 (1d10) cold damage. A target that is hit by one or more of these attacks has its speed reduced by 10 feet until the end of the Myrmidon’s next turn