Vastweld, The Colossal Guardian - Untouchable with Twister until he move around and barely after

Got this boss
Vastweld, The Colossal Guardian - He is Untouchable with Twister until he move around while he can attack me. After he move around the platform you can touch him by sending twister perfectly in front of him if you get a little angle they dont touch him. Barely able to do damage no other boss or like that.