Enigma is a very dangerous Phantom and doesn't hesitate to attack people if they attack her, so this suggests that she has a merciless personality. However, she is rather smart and instead of attacking directly, she usually comes up with plans and with her immense power, she has the advantage in most situations. At the final fight she gave huge respect for Haruhiko, and before she dissipated into nonexistence warmly told him: "I enjoyed the time I spent as your mother." This was probably true