The changes for Succession Sorceress on the global lab seem pretty solid, lower cooldowns for Bloody Calamity and Imminent Doom allow us to play more aggressively to compensate for the lack of defense outside Iframes, that's definitely a really good change however the Scattering Shadow and Bloody Contract and Sinister Omen need to be addressed, the former is cool but the only way we can benefit from it is having a static enemy with forward guard, it's basically a suicide kick if we consider using it to get behind in order to land a cc, as for Bloody Contract being able to sacrifice mana in order to gain hp is a cool concept, but to stand unprotected for 10 secs in order to recover your hp is definitely not realistic, Sinister Omen is no different than Bloody Contract, summoning for 2-3 secs while unprotected in order to hope for the Omen to land a single hit never ends well.
Here's what I suggest regarding the three skills that I believe need to be changed.
Giving Scattering Shadow any kind of protection will definitely solve the issue even if the cooldown is increased.
Changing the way Bloody Contract works making it similar to Dark Trade will definitely make the skill worth using, something such as instantly offering 30% mana in order to recover 10% Hp or Hp over time would be cool, even if the cooldown is long.
Sinister Omen is a really cool concept but instead of a summon that never lands hits, it could work as an area around the caster that attempts to land the debuff for instance once every 3 secs, or we simply cast it and it keeps debuffing enemies in that exact area we casted it at, but if that's the case the debuff % has to be decreased as it will turn out to become a skill that needs to be nerfed, it could also work as an area that increases the damage done inside it instead of debuffing enemies or increases the caster's attack speed if they decide to fight inside the Omen's Zone.