A build designed to defeat Malak in a single turn. This is absolutely doable, provided the following two conditions are met:
1) You attack him from behind (damage bonus from sneak attack).
2) At least three of your attack rolls are within threat range (40% chance). Your threat rolls, however, have a 100% success rate as long as your main/off-hand lightsabers have an attack of 37 or more.

Class combination / level distribution: Lvl 7 Rogue / Lvl 13 Jedi Guardian

Start attributes:
STR 14 2 (all remaining 5 attribute points were invested in STR)
DEX12 1
CON 14 2
INT 10 0
WIS14 2
CHA14 2

Article:
Retinal Combat Implant (Malak's critical hits deal significant damage on Hard difficulty)
Advanced Biostabilizer Mask (prevents you from being weakened by Malak's Master Critical Strike if your Fortitude save is insufficient)
Dominator Gauntlets
Robes of the Star Forge
CNS enhancer
Lightsaber (Mantle of the Force, Solari, Opila)
Lightsaber (Heart of the Guardian, Upari, Opila)

Talents (10 in total):
Advanced Critical Strike – Master Critical Strike
Two-Weapon Fighting – Improved Two-Weapon Fighting – Master two-weapon fighting
Weapon Focus: Lightsaber – Weapon Specialization: Lightsaber
Implant Level 1 – Implant Level 2
Advanced Jedi Defense

You can swap the Opila crystals for a Sigil (1d8 energy with MotF/HotG) or a Krayt Dragon Pearl (1d8 energy with HotG), but it won't make much difference. Don't upgrade your lightsabers with crystals that grant fixed damage bonuses, as these are not multiplied by critical hits (Opila is an exception – it grants 2-12 massive critical hits that compensate for the fixed damage bonus).

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