bloodline is a little problematic, as it is a concept in three quite large games and neither shares anything but the name:
- vampire-the-masquerade has Bloodlines as "sub-Clans". For example, Kiasyd are considered generally a bloodline of the Toreador. The Assamites even sport a whopping 5 Bloodlines, Castes + Antritribu.
- Generally, bloodlines use alternative powers than their host clan
- the Questions asked here seem to delve into the lore of how one branch or another was formed
- vampire-the-requiem Has Bloodlines which are similar but distinct from VtM.
- dungeons-and-dragons where Bloodline is... something that somehow...
- pathfinder has Sorcerer-boodlines and Bloodrager-Bloodlines, which ways how they are empowered.
What should we do? There is little to no chance to get those things somehow can fit under one hat for an overarching definition, as called for here - So Is there some solution?!