Guess it's CR 8! You're also right about the range for the mind flayer. I didn't even look at that comparison.
Tactics: Uses psychic blast first as a ranged attack, then enters melee? Judicious use of psionics?
Let's see...
The monarch scorpion is an ambush hunter, hiding beneath the sand to attack victims who wander too close. An active monarch scorpion normally casts
alarm,
blur and
detect magic every minute or two; its copious use of silent
alarms means it often knows potential victims are nearby long before the creatures notice the scorpion. Given time, it will cast
spell resistance on itself before combat - especially if it
detect magics on its opponents.
A monarch scorpion typically opens combat by closing to just outside melee range and unleashing a
psychic blast or
greater shout, trying to stun as many opponents as possible. Over the next rounds, it attacks with its natural weapons or a psionic power as the circumstances dictate. A monarch scorpion's favorite psionic combat tactics are using
vampiric touch on grappled opponents to absorb damage from attacks,
dominating enemies and ordering them to kill their own allies or submit to being eaten, or releasing another
psychic blast or its
greater shout.
This monster is so vicious and malevolent it seldom breaks off from combat, usually because its enemy is so powerful and resistance to stunning and poison attacks that continuing to fight would be suicide. On these rare occasions, the monarch scorpion usually just runs away as fast as it can.