from what i've seen, hes pretty good with his stick and taking away from the puck and he does backcheck, has the speed to be able to so that helps
theres definitely nothing holding him back in his defensive game
I don't know if i would say there is nothing holding him back defensively. There are definitely items that need to be addressed.
In his first partial season with the Wolves, he was caught standing around too much away from the puck, in his own zone. Just watching the play pass him by. But then as you mentioned there were times, where he is so aggressive in attacking the puck, lifting sticks and creating turnovers. He looked great at those times. A mixed bag, i'd say.
I have recently watched all of his games with the Wolves the past season. And i found his defensive play to be lacking. There were about a handful of distinctly poor giveaways that i remember off the top of my head. Two of them were facepalm worthy, where he is on the half wall, not much pressure, and clears the puck up the middle of the ice, right to an opposing defenseman who easily picked it off and it led to a scoring opportunities. The others were simply him not winning battles along the boards or being first on the puck. I found he was simply a passenger defensively and offensively this go-around, not as aggressive as the first stint. But he did find himself on the PK a couple of times, where I thought he was positionally sound.
I don't expect Selke caliber defense, but i think he needs to tidy it up.