Tera is a cyborg who's brain is 250 years old and fought in several battles in the past. He nearly died at the age of 63 from shrapnel from an explosive but was transferred into a robotic body where he fought in 2 other wars before retiring. His "sister" Epsilon is actually his great great granddaughter, they pretend that she is his sister to protect his identity. He hasn't told anyone about any aspect of his life besides Epsilon or Red Wing , his closest friend. Other than them, Celestia is the only other pony who knows this. He is very strong due to his robotic body and is very skilled in hoof to hoof fighting and can even disable magic temporarily with a special implant. He has a very tactical mind but still uses terms from long ago. He is a master in all forms of hoof to hoof fighting and teaches his tactics and skills to Epsilon, who in return, runs her own fighting school to teach his tactics to others. He is very knowledgeable about most things including; magic, spells, battle strategy, using guns, and even raising children. Even through all that he is very kind and caring and tries not to get into fights. He raised Epsilon for most of her life when he found her on his doorstep and took her in and eventually discovered that she is his great great granddaughter.