I have created a Pathfinder "Monster Makeover" version here:
Pathfinder Beholder
I think it would be a good idea for you to read the whole thread. Your take on beholder has several issues, which may have been absent otherwise:
- glass cannon - the beholder dies during the first round. It dies accomplishing nothing if it loses initiative within charge distance of a barbarian or fighter (low hitpoints). It dies (or is removed from combat) without doing anything if it loses initiative to a wizard with save or die spell due to abysmal arcane defenses.
- Baleful Eye (Su) features autopass DC (meaning - any spellcaster will ignore the DC). Additionally, the DC is calculated incorrectly as ability based DC goes as follows: 10 + 1/2 HD + ability bonus.
In this case base DC should be equal to 10 + 6 + 3 (=19), with +4 racial bonus: 23.
13th level Wizard is likely to have +7 intelligence bonus, with total modifier to spellcaster check being equal to +20.
Unfortunately, spell DC formula does not work for concentration checks, as spell DC is compared to D20 + base save + ability bonus, while concentration check replaces "base save" with level, which is usually around double of "base save".
IMHO, you should leave it as antimagic cone. It's simpler, involves fewer rolls and spellcasters are still free to walk away.
- Eye Rays (Su) should be more concise and clear. The number of rays should be listed in both creature statblock and defintion of ability. The names of the rays are confusing (Stun ray doing Charm Person, for example).
- Telekinesis Ray - just replace it with a Bull Rush ray, copy Black Tentacles mechanic and replace Black Tentacles effect with Bull Rush maneuver directed as per Beholder's whim.
- while we're at this, Beholder should use Charisma as its base spellcasting ability (it's not mandatory, but default monster building assumes Sorcerer as a base arcane class for monster abilities), and caster level should be listed in appropriate section of statblock.
- Sustained Barrage conflicts with action rules of D20. If you really want the creature to act multiple times per turn, you have immediate actions for this, and all you need to do is to state something like:
Sustained Barrage (Ex): Glaring Tyrant may, as an immediate action, fire an eye ray. It cannot use an eye ray it has already used during this round.
Regards,
Ruemere