I have not been around long enough to collect all the legends. I don't know if this combo has been done here yet.
Passive: Mirage - invisible man revive trick.
Tactical: Crypto - Drone to recon enemies.
Ultimate: Rampage - Sheila for the crazy gun fun.
What kind of character traits would I like to see in the future? Well this is my idea (call it fan fiction, just in case EA has it on the whiteboard) for an good Legend.
Trickster class
Passive: Can use the empty storage bin to hide inside, close the lid and wait to be found Surprise!
Tactical: Disguises themselves as a gold death box.
Ultimate: Surreal Vision, both enemies and allies suffer "wavy drunk vision" in a 50 meter circle around, while the legend is the only one immune for 15 seconds.