Phyladeiliaphobia describes an intense fear of failing to protect or save others, which can cause significant anxiety and/or panic.
If you have Phyladeiliaphobia, even thinking about allowing someone to come to harm may cause fear, discomfort, and/or anxiety, even if they are a complete stranger to the you.
Phyladeiliaphobia is an extreme or (depending on the context) irrational fear or phobia of failing to protect other people, especially when the person is in mortal danger and/or are a loved one. This may even extend to fictional characters, such as stories that are interactive, non-linear, and have optional deaths.
It's reasonable to expect a certain degree of discomfort or dislike over the concept of a loved one coming to harm when you could've prevented it, people with Phyladeiliaphobia experience a somewhat constant anxiety that they might fail to protect anyone from a dangerous hypothetical situation, which may evolve into a full-blown panic attack should they fail to protect others if said dangerous situation comes to pass, even if it isn't inherently life threatening.
In efforts to control or manage agitation and/or anxiety caused by Phyladeiliaphobia, sufferers may disregard their own safety in situations where it may be more advisable to prioritize their own safety instead. Due to this, others may label them as "heroic" or "good samaritans" but their actions are just as often for their own benefit as for the benefit of others.
The term is from the Greek: φύλαξ, phýlax, meaning "guardian, protector," δειλία, deilía, meaning "cowardice, fear" and φόβος, phóbos, "fear".