I must admit I never really gave that much thought to Jace's backstory until a couple of months ago and given that the character was living on borrowed time, I thought it would be interesting if I gave Jace a phoenix-motif. First off, the phoenix is probably bar none, my favorite mythological creature because I am a pyro and because I was always intrigued with its association with rebirth, so I believe you know what that implies.

(Though we only discussed it via instant messenger, Cam hypothesized that Soma "remembered" the data from Project MERCURY when he scanned Jace in "Dark Dragon." While I am not entirely certain how the mechanics of it work, but I imagine poor Soma would be quite disturbed if he got more of glimpse into Jace's forgotten past.)
Another important note to make is that ancient Egyptian and Hellenistic mythology associate the phoenix with Ra and Apollo, both sun gods. Though I have not integrated it into any thread yet, Jace/Ben's father, Aaron (a chosen of Yggdrasil himself who ran away to Mirai for a few years) had a saying, "The sun will always rise, no matter how much the darkness tries to hold it down." While most associate the Crest of Courage with the sun, the Crests of Hope and Light are equally symbolic of the sun, which in itself is a part of a cosmic cycle of death and rebirth considering how the solar system is made from the remnants of a supernova. In my mind, Jace (as the phoenix) is a reminder that the sun has always risen through the eons and even when the night falls, the stars are always there to guide him, which mean there is always hope. Hence it comes as no surprise to me that the Digimental of Hope bonded with Jace so easily nor is it any surprise that the Crest of Hope appeared shortly before he entered the Sea of Memories. The phoenix, being a symbol of the sun and rebirth always functioned as a symbol of hope. In Jace's case, hope for new life and freedom from his grandfather's control.
It should also be worth noting that Jace's fascination with the Flash may not be that coincidental either. From what sources I looked at, the plumage of the phoenix is colored red and gold, sound familiar? Plus, speedsters in the DC Universe are notorious for their inability to stay dead. Wally West himself escaped from the Speed Force at least twice. Bart Allen returned to the living (though he was "bottled" in a lightning rod with thanks to the Legion of Super-Heroes) in Legion of Three Worlds. Hell, Barry Allen returned after twenty-three years in Final Crisis. So if word of an LoE manifestation of a fiery raptor having appeared around Jace in the past gets out, I wonder if the other tamers would take that as a good omen.
Finally, I thought I would address the motifs taken from Norse mythology. I thought it would bear mentioning that I have Norwegian ancestry on my maternal grandfather's side so I had a deep fascination the country and its history since I was nine or ten (which was coincidentally around the same time the Winter Olympics were held in Lillehammer.) First, it bears mentioning that Jace's grandmother is from Denmark and his maternal grandparents immigrated to Canada from Norway. It is not in his bio at present, but I will add it later. Second, though the phoenix is taken from Hellenistic mythology, I see Jace's LoE manifestation taking from inspiration from the unnamed eagle attested to in the Prose and Poetic Eddas that stays perched on the branches of Yggdrasil. Though the Phoenix is also depicted as a heron or a peacock, I chose to make it an eagle and fuse it with the unnamed eagle from the Norse myths as a way to honor Jace's (and my) heritage. Third and lastly, I find a curious parallel between "The Dark Dragon Returns" and the story of Balder whose death ultimately led to Ragnarok. It is not a perfect comparison, but Jace's death was brought on Pendragon's machinations via the connection between him and Soma, which is vaguely similar to how Loki tricked Hod into throwing the dart (or spear) of mistletoe that slayed Balder...
...Come to think of it, Balder does return to life after a new world rises from the ashes of one destroyed in Ragnarok. Hm, ashes? Sounds awfully similar to the phoenix motif, does it not?

Anyway, I believe I have rambled on long enough and earned some more mileage from my English BA. I hope it gives the rest of you reason pause for reflection on your respective characters.