In target process and many other tools, one can link an entity(story, task, feature etc) to any other entity and mark that link as a blocker, dependency, relation or link).
In Fibery one cannot do this currently in a generic way. One has to be explicit and define a type of entity as a blocker or relation. This is a bit limiting and verbose.
It would be good to create a link to any item in fibery and mark it as a blocker, dependency of, target of.
Thanks for the suggestion, Paul! Noticed 
Btw as a workaround if you have multiple types that can be blockers, you can use mentions and bi-directional links.
How do you feel, can that help you somehow?