IMC has released a new update preview here. Preview contents may be subject to further changes.
1. New Stances for Catherine
Catherine STR will get a new polearm stance [Brandish Arm], which can also summon Mighty Victor. Catherine DEX will get a new bayonet stance [Split Shooter]. This will be a long-ranged, wide-area effect. She can also summon Crown Lloyd.
Catherine INT will get a new dual elemental (LOE) bracelet stance [Activator], featuring medium-range, wide-area, and fast-casting skills. She can summon Lady Sasha. Catherine the Summoner will get a new controller stance [Puppet Master] to summon Mighty Victor, Crown Lloyd, and Lady Sasha. She can self-destruct the dolls. The summoned dolls become more powerful at higher levels, and will be destroyed when changing stances. The stance book is expected to be available via quests.
The stances are added in v10.14.0. Added links above to stance screenshots. See Play Forum articles on [Brandish Arm], [Split Shooter], [Activator], and [Puppet Master].
2. New Stances for Panfilo & Karjalain
Added [Diable], a new sword (or sabre) + fire bracelet stance for Panfilo. (This stance seems to be named after a cafe - see here. The Korean stance name is 디아블 as opposed to the raid boss 디아블로.) It has a buff skill, probably involving fire, and can inflict status.
Added [Fleuret Glacier], a new rapier + ice bracelet stance for Karjalain. It has its own buff skill, and seems to be more directed for single-target. These stance books will be available via quests.
The stances are added in v10.14.0. Added links above to stance screenshots. See Play Forum articles on [Diable] and [Fleuret Glacier].
3. Dr. Torsche's Mansion Annex
Dr. Torsche's Mansion Annex will be revised in v10.12.0. The drops include strange "accessories" (probably Strange Tube/etc.), and rings for Catherine's new Expert stance skills. The map will no longer be a premium dungeon and will be subject to Secret Society War. It will revised for Veterans-Experts.
See 새단장한 토르쉐 저택, 별관에 가면 특별한 선물이! for Play Forum article of the revised map.
4. New Character & Area
A sneak preview of a new character and area. The character is an officer from Bristia. More details will be provided in future update previews.
5. New Squad & Costume Options
Squad feature has been revised to allow quest kill counts even in different squads during missions. Game Options (Alt-O) will have a Hide Costumes option.
Adelina's Revenge quest will continue in future update preview. Uh, Bardi's son Tora becomes recruitable.