It isn't easy to utilize Thanalorian Blade's EXECUTE. If the target has 3 Health points and 1 ARMOR, it cannot use EXECUTE. Situations or assistance from other monsters are required to support the use of EXECUTE.
- Such as using Magic monsters to attack first the target that has less than 5 ARMOR (2 ARMOR if they have SHIELD ability) >> and if 2 Health points remain, Thanalorian Blade can use EXECUTE.
- Or use a Melee or Ranged monster with SHATTER to attack first if the target has ARMOR and 6 Health points (4 if it has SHIELD).
- You can also use a Ruleset that removes ARMOR on all monsters (UNPROTECTED).
For Olivia it can be used even at level 2 (because she already has a Mimic). but it is true what you said, at that level it is still too risky because her Health points are still too small which can make her a target for OPPORTUNITY monsters or take damage from BLAST.