Losing a limb in a dream often symbolizes a loss of capability -- a skill, role, or sense of independence you're afraid is being taken from you. It can surface during a major life change, when you feel less equipped to handle what's ahead than you did before that change began.
For domination use Mars, because it has influx and quick response in this and other aspects, and it means renovation and growth. - Picatrix (Andalusia, ~1000.AD)