1. Did he or could he had gone though regeneration? He started that he was a Time Lord but after the War Lordhad him killed his body is removed and he is not seen again or talked about during the War Lord's or the Doctor's hearing other than when the War Lord states that he was a Time Lord.
2. Could hebe the same Time Lord that later went by the name The Master? Like the Master he knew the Doctor from their past. He would have a reason to hate the Doctor. He would need to hide from the Time Lords.
3. If 1 is true could he still be alive and show up in the new show?