While fighting the boss fight on multiplayer; only the host can see the Deathrays of Ender ability; all other laser and fire based abilities would sync fine, but this ability would lead to teammates dying. When trying to res them; the other AoE spells would fire, making it impossible for the other teammates to survive any attacks. After confirming with my other two players, they had never once seen the Deathrays of Ender ability used after sending them screenshots where I saw it numerous times. This happened across multiple attempts against the boss.