Here is the guide I followed. I give all credit to Bladestriker in the Alla forums.
For a nearly sure fire win against Bst Maat just do this:
1)You should bring the following items:
Life Drinker Lars x2
Opo-opo Necklace
Sleeping Potions (stack)
Hedgehog Pie (vastly better then sushi)
Top Knotch Potions (Vile Elixer +1, Max Potion, whatever you can find they can be rare on AH)
Persikos Au'lait x2
Blink Band
As Much +Acc as you can equip!
Str/Atk where there is no +Acc gear
Icarus Wing
A bunch of Hi-Potions +2
2) Call LDL, buff up and sleep to 100 TP
3) Send LDL after Maat's Pet, not after Maat this is vital.
4) Do not take any action whatsoever on Maat, I repeat to not touch him!
5) Maat will link on his pet and pull LDL off.
7) Attack his pet, get one hit in then Rampage. If it is a Mandy then melee / use potions as needed to survive.
8) Once the pet is dead asess the situation to see where you stand, you may want to wait to see what Maat's second pet will be before proceeding. The KEY consideration here is that Maat Will Not Attack You if you are out of sight and have taken no direct action against him when/if LDL dies!!! So you can move up the tunnel a ways and /heal, use potions, pop another hit of Blink Band, etc... without gaining hate!
9) IF all is well and he pops a bunny for a second pet then good, pop that wing and finish him off.
10) If not and he calls his second Mandy of the fight and has been Asuran Fist spamming your pet (happened to me - 3x Asuran Fists on my pet in < 30 seconds
) then just wait for LDL to die and take no action against either Maat or his new pet. They Will Not Attack You when LDL dies!!! Then just pop your wing, heal and buff to full (do this before LDL dies not after) and proceed as per 4-9 for a pretty much guarenteed win as long as you keep your cool.
Frankly I cannot see how you can fail with this strategy as long as you prepare as described. You may or may not need all of those meds, I used very few, but you can always sell what you do not use and you will be more then glad that you have them if needed.