Got mauled on my first few tries, but hey, I did not know what to expect.
Using summons is generally not a good idea because it triggers Bodhi to cast some instantanous spell that detonates in an unholy area-of-effect explosion that can easily deal 20-40+ damage on Core Difficulty. Extrapolating the figures from Insane Difficulty where it was 40-80+ damage.
It is unlimited and kills your summon instantly. Not fun.

[img]tongue.gif[/img]
However... there is a way to cheese the battle. A method so cheesy it reeks to the skies.

What if... I told you that you can win this battle on Insane Difficulty with minimal effort and suffer not one HP of damage?
Impossible? Hardly so.
You need one Mage/Sorcerer capable of casting Abjuration spells.
Yes... it is always the Wizard and his/her cheesy ways is it not? 
[img]tongue.gif[/img]
Bodhi spawns with a group of Undead Archers( UA) that
SURROUND her. Since they cluster around her, and add to the fact that they do not move if their target is within range, Bodhi is
TRAPPED.
ABUSE this to your advantage. Do
NOT attack the UAs. In fact... prior to summoning Bodhi, have your suitable Wizard cast Protection from Normal Missiles and position him/her close, but not too close, to Bodhi's spawn zone. Just make sure that he/she will be the nearest target for the UAs when they arrive.
Watch in amusement as the UAs futilely attack your Wizard as Bodhi squirms "helplessly" among them. Have your entire party switch to ranged weapons and target Bodhi, and Bodhi only.
Do not dilly-dally though. Each UA only has 20 arrows, so this gives you one turn to turn Bodhi into a pincushion. More than enough time in my opinion. Use equipment like Azuredge, Melf's Minute Meteors, Tansheron Bow, Heartseeker, etc... with ammunition like Acid Arrows or just plain old Arrows +2.
Using this method... you can bring Bodhi to near-death and grin with satisfaction as she slinks away licking her wounds. Note that you can still use this tactic without a Mage. Just use the party member with the best AC value to take the hits from the arrows. Drink healing potions as necessary.