Aeya Longmirror is a changeling spy, who works for a secret agency in Canterlot. Skilled in, along with expert marksman skills, she was a very successful agent, who would always get her mission done. However, despite being told that the agency was for a good cause, she found out that the agency was secretly backing different armies and militias (including ones she was sent to stop), for political gain and manipulation, she decided to quit and try and air the secrets out.
Unfortunately, this put her in a hitlist, and she only had time to grabs her weapons and a few other things before fleeing. Now, she is now on the run, blending in with different groups in order to try and find the agency and put a stop to them.
(Her chageling form is her normal form, while the pony and kirin forms as her main disguises)
The robot is a new assassin the agency is sending after her, dubbed “AEYA 2.0”. It has been programmed from data it has gathered on her, and is now being sent to put a stop to her by any means nessicary, Without feelings and highly strong armor and reflexes, it is a fearsome force.
Hehe X)
But lucky her to be an alicorn changedling, those are not that common in the show.