There’s still a lot of confusion about how to perform BK combo skill.
This will teach you how to do all forms of the BK combo properly at high speeds. But before you can do combo, you must do Marlon's Ring of Honor/Dark Stone quest.
There are many types of combinations for the combo.
They are as listed,
FIRST - Weapon Skill + Twisting Slash + Death Stab
SECOND - Weapon Skill + Twisting Slash + Rageful Blow
THIRD - Weapon Skill + Rageful of Blow + Twisting Slash
FOURTH - Weapon Skill + Rageful of Blow + Death Stab
FIFTH - Weapon Skill + Death Stab + Twisting Slash
SIXTH - Weapon Skill + Death Stab + Rageful Blow
Basically the last 2 skills in combo can be any 2 orb skills (except Swell), but the first skill must always start with weapon skill. The two most powerful forms are the first form and the second/fourth form.
The FIRST form being the most powerful because of the speed that it is executed at. If done properly, the first form can be executed 2-3 times per second. The downside is that you must keep your mouse hovered over your target while you execute the 3 skills or else it will not work. I find doing this form is effective against opponents that stay still while using attacks that involve range, such as SMs, Elves and combo-less BKs who stay still while attacking with skills. If you're fighting a bk who uses this form a lot, you might have a hard time keeping your right mouse button down, your cursor on the target and continuously switch skills because of the constant moving around.
The SECOND form is commonly used by BKs who have knowledge of how to do combo but cannot execute the first form fast enough because they lag a lot or still cannot handle the first form. This form is slower and doesn't require you to have your cursor over the target continuously like the First form. This combo form will execute at a slightly longer range than the first form and have an AoE (Area of Effect). This form is very effective when you lag a lot and cant switch keys fast enough during battle.
The FOURTH form is basically a slower variation of the first form.
Now, how to execute combo.
Make sure you have the skills you're using, hot-keyed 1-3. In this example, I will be doing the Second form so I'll hot key weapon skill to 1, rageful blow to 2 and twisting slash to 3.
First, hold down your right mouse button over your opponent so your bk is executing the weapon skill. Hold it for as long as you want. When you're ready, press 2. That will execute Rageful Blow after the weapon skill. When you see the ground beginning to crack from the skill, immediately press 3 to execute twisting slash. When twisting is executed at the end and combo is successful, you should see a large blue explosion and a loud cracking sound.
If you feel the second form is too slow, let's move onto the first form. Hot-key weapon skill to 1, twisting slash to 2 and death stab to 3.
Again, start at skill 1 and hold down your right mouse button on your opponent. Hold it for a few seconds if you want, then when you're ready, immediately press 2 then 3. Then time between 2 and 3 has to be in an instant, you cannot delay or else combo will fail.