Warlord's Bloodlust and Ability Crits
Is there any reason that champions like Anivia, Karthus, Soraka, etc, cannot use this mastery? I feel like it was a missed opportunity there particularly since the Ferocity options for Mages seem a little inflexible. You could even support this by doing a sweep on what qualifies as an ability crit - e.g. triggering LeBlanc's Sigil of Malice; triggering an empowered Pillar of Flame; triggering Z-Drive and Organic Deconstruction; triggering Heimerdinger's stun; etc.