Among the items designed for Mages, the Cosmic Engine is quite a unique piece. With its skill cooldown reduction and movement speed increase effects, this item is well-suited for Mages like Ryze, Cassiopeia, Vladimir… These characters need to move constantly in fights to maintain positioning and deal maximum damage.

The weakness of the Cosmic Engine is that the movement speed boost effect only activates after hitting enemy champions 3 times (with auto-attacks or skills). If opponents can dodge the player’s skills, this effect is very difficult to activate. Perhaps this is why Riot Games decided to redesign the passive of the Cosmic Engine on the test server.
Specifically, characters with the Cosmic Engine will receive a 2.5% movement speed increase each time they deal damage to enemy champions. This effect can be triggered every 1.5 seconds and can stack up to 4 times. When fully stacked, players will gain an additional 10% movement speed from the Cosmic Engine item.

As soon as the new effect of this item was announced, Riot Games faced a significant amount of mixed feedback from the community. The reason stems from the fact that this new effect is not suitable for characters that were already utilizing the Cosmic Engine effectively. The limitation that champions with short cooldowns like Ryze, Cassiopeia, Vladimir… can only receive 1 stack every 1.5 seconds is a major drawback.

It is important to note that the duration of fights in League of Legends (LoL) is relatively short. Requiring a Mage champion, who does not have much defensive capability, to continuously deal damage for 5 seconds is almost impossible. As a result, the effectiveness of the new Cosmic Engine in actual combat is significantly lower than that of the old version.
Hopefully, Riot will make reasonable adjustments before rolling out the ‘new’ Cosmic Engine to the official server. They might consider options like reducing the maximum stack acquisition time of this item to allow better interaction with Mages like Ryze, Cassiopeia, Vladimir… for example.