system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel] Shield gains access to two updated versions of the SSS which are 100% guaranteed to create two more Caps at 0% failure rate but they can't be replicated whatsoever. Every Shield agent is willing, but who would be the most logical candidates?
gpt
You stage a shooting at SHIELD headquarters and choose from the most heroic of the noncombat personnel. You'll want somebody like a mailroom clerk who shields their friends from a hail of (mercy) bullets or an administrative assistant who "dies" holding a door closed. 

You want people who are selfless and good. All other requirements are secondary.