Mana cut is not a status ailment.
Status ailments are indicated by the enemy hero putting a little symbol on your hero card. Mana cut (from Guinevere and bauchan among other heroes) does not put a symbol on your heroes and thus is not a status effect.
See here for a full list of status effects (both positive and negative)
There are only 3 heroes who have the potential to stop mana cut from an enemy special skill:
- Seshat who has an innate resistance
- Ursena special reflect will bounce mana cut back at yellow mana cutters (moot as they will have 0 mana after firing their special but hey)
- Mitsuko would do the same as Ursena IF there was a blur mana cutter.