Presley Gerber's ex-girlfriend is remembering him as a superhero in her life ... sharing an image of him showing off his action-star skills as part of her emotional farewell.

Actress Jewell Farshad posted about the late 27-year-old late Sunday evening -- about a week after Presley was found dead inside a Santa Monica sober living facility -- recalling the time they went to a shooting range.

In her caption, she called Presley a "real-life superhero" and "battleground partner."

Jewell further expanded on those labels in a follow-up post ... explaining they met in actors' tactical and stunt training ... and saying he helped her conquer her fear of firearms.

She says the two were battlefield partners in stunt training -- roles that require a ton of trust. She says she'll never forget Presley standing by her when she most needed someone.

Jewell notes the pair dated ... but ultimately split up when life took them separate ways. Despite their breakup, she says she thought about Presley a lot -- and considered texting him in the weeks before he died.

She also shared a video of a butterfly that has visited her every day since Presley died ... which she says is a sign he's still looking out for her.

As we've reported ... Presley was found dead Sept. 20 in a sober living facility. Sources told us he appeared intoxicated while being admitted to the facility the night before. A cause of death has not yet been revealed, though the autopsy is complete.