It’s unclear whether by accident or design, but Riot Games continues to allow “unstoppable” compositions like Vanguard/Guardian – Mystery to dominate in version 10.12. With the addition of Cassiopeia, this composition has completely overcome its late-game damage drop-off weakness, becoming an unbeatable tank.

Therefore, in their latest updates, Riot Games has introduced some noteworthy adjustments targeting Mystery and Cassiopeia herself. All these changes aim to reduce the safety of this champion and give opponents more chances to penetrate the backline and counter Cassiopeia. Specific changes include:
Spy
(4) Attack speed increased from 70% to 80%.
War Machine
(2) Recovery or bonus damage ability increased from 70 to 75.
(4) Recovery or bonus damage ability increased from 160 to 175.
(6) Recovery or bonus damage ability decreased from 450 to 400.
(8) Recovery or bonus damage ability decreased from 900 to 880.

Gunner
(4) Additional hits received increased from 5 to 6
Mystery
(4) Magic resistance for the entire team decreased from 125 to 110.
Blademaster
(6) Activation rate for bonus attacks decreased from 70% to 65%.

Illaoi
Shield and magic resistance gained increased from 20/30/50 to 30/40/60.
Teemo
Mushroom damage decreased from 125/175/600 to 125/175/550.
Slow duration decreased from 4 seconds to 3 seconds.

Gnar
Stun duration when using abilities decreased from 2 seconds to 1.5 seconds
Health gain when transforming into Mega Gnar increased from 750/1250/2500 to 750/1250/4000.
Attack damage when transforming into Mega Gnar increased from 100/175/400 to 100/175/550.

Nautilus
Stun duration increased from 3/3.5/4 to 3/3/5.
Master Yi
True damage to 3-star champions decreased from 75/100/200 to 75/100/175.

Nocturne
Damage to 3-star champions increased from 200/250/350 to 200/250/400.
Cassiopeia
Damage skill decreased from 700/1500/4000 to 700/1500/3000.

Jinx
Bonus attack speed from skill decreased from 60/75/100% to 50/70/100%.
Riven
Shield amount from skill decreased from 250/400/1000 to 225/375/1000.
