How to deal with Sefris/dungeon/reanimator deck?

Just played a commander game vs this and by turn 3 Sefris was on the board, the opponent rushed a dungeon, cycled 2 big creatures to the graveyard and used a spell to summon them on the board. I had a 1/1 on the board and suddenly have to face a 8/8 and 8/7 ON TURN 3, how the hell do I deal with this?

I tried a board wipe but the player also had a card that resummoned every creature that died...

Every card that deck played triggered like 5 abilities every turn, rushed a dungeon, got free creatures and had tons of mana...

Is the only solution to this deck to just spam graveyard removal, cause that sounds pretty boring if its the only counterplay...