Once you are one Hook away from instant death, Blood Rush activates:

Press the Active Ability button to lose a Health State and instantly recover from the Exhausted Status Effect.
Causes the Broken Status Effect for 28/24/20 seconds, while you are automatically healing back to Healthy.
Cancels the healing effect upon taking damage.
Blood Rush is disabled for the remainder of the Trial after use.

When injured, healing another Survivor without using a Med-Kit also heals you with a Conversion rate of 40/45/50 percent.

Every 15 seconds you are within the Killers Terror Radius, while not being chased, Stake Out gains 1 Token, up to a maximum of 2/3/4 Tokens.

When Stake Out has at least 1 Token, Good Skill Checks consume 1 Token and are considered Great Skill Checks, granting an additional Progression bonus of 1 percent.
Great Skill Checks do not consume any Tokens.

You start the Trial with a Progression penalty of -25 percent for succeeding a Good Skill Check while healing another Survivor.
Succeeding a Good Skill Check while healing another Survivor grants 1 Token, up to a maximum of 3/4/5 Tokens.
Each Token grants a stack-able Progression bonus of +15 percent for succeeding a Good Skill Check while healing another Survivor.
Suppresses Great Skill Checks while healing another Survivor.
Autodidact remains inactive while healing another Survivor using a Med-Kit.