A terribly imbalanced card with little counter play.
I always run into people with multi mask changes in hand. The moment they play Anki, they win almost instantly.
Enemy controller? MASKED CHANGE!
Wall of Disruption? MASKED CHANGE!
Widespread ruin? MASKED CHANGE!
Trap hole? MASKED CHANGE!
VOID? MASKED CHANGE!!
It doesn't matter if I play a trap/spell or even monster effect. I can't seem to get over them because they'll just dodge any counter by playing a second mask change to avoid the counter and then a third to finish you off.
Semi-limiting both Celestial and Enemy Controller, together with nerfing Restart and releasing Silent Magician. All those things where a pretty heavy nerf against them. They're still powerful, however.
Here is how i countered my opponent that used Mask change. I let them attack me with drilldark, they MC into Anki. they attack with anki. I use sphere kuriboh, but they MC into anki again. I use bacon saver, but they again mask change into a third anki only to get cockblocked by Fiendish chain.