Anti-Mill card recommendations?

Hello! I am wanting to build an anti-mill deck for some friendly games. My fiance runs a Mothman deck, and another friend runs a lifegain Hope Estheim deck. I can kinda deal with Mothman and have beat him many times before, but when the Hope deck comes out we know we're getting decked within 7 turns. The first time he brought that deck out, I scooped on turn 3 because he got a very lucky draw and had us milling 30 cards and then taking damage equal to the amount of creatures milled that way and I wasn't in the mood for that.

I don't want to hate milling as much as I do, and I don't want my friends to feel like they can't play their strong decks knowing that I'll just scoop, so I really want to build a deck that can counter lifegain or play from the graveyard. I was looking at Nethroi, Apex of Death as a commander but I'll take any recommendations. I like to play pretty passive, just spend my time building up my mana and board and pretending like I'm not a threat and then taking everyone out within a few turns.

Deck List that I was working on: https://moxfield.com/decks/MmvDEM_Yj0atuJf7Zv_iUQ