worked my butt of to get a couple of B/C Tyranitars so I could solo Gengar. My first attempt was disaster. I did way worse than I had with B/SE. Figure I must be doing it wrong.
how do you use a three bar move.
Answers
As the others have already pointed, Gengar's moveset will be the deciding factor. As to how to use a 3 bar move, I usually spend the first one ASAP or wait for the second bar to fill. That way the 3rd bar or now the 1st bar is full and I can spam again. I actually prefer Crunch over Stone Edge for some reason... probably because if its flexibility since I can use 3 x 70 damage for the same energy as 1 x 100 Stone Edge. The only downside is the delay. Still... It doesn't hurt to have both... Considering after Generation 2, most Legendaries will be mostly Psychics. Now if Tyranitar can learn Rock fast attacks, it would be an entirely different story.
With 3-bar moves, I generally use the first charge move as soon as possible because the defender will pretty much guaranteed not have a charge move prepared yet. Then I'll wait to see what the defender's charge move is and adjust how I attack based on that. If it is something that I resist and can tank, then I'll spam attack with little care for dodging. If it is something more dangerous, I'll be more careful to dodge and use charge moves when defender is less likely to use a charge move.
Today, I soloed gengar using 2B/C ttars, C/FS Zam, and 1.5 C/FS espeons had another a ZH/PsyB espeon that didn't get used.
The gengar had Focus Blast. I usually can charge and use two crunches before any 1 bar boss move. But the first Ttar got blasted straight out. So I adjusted to using two bars following an easily dodgable FB. If gengar stops moving, look for the "sunlight" then start dodging. The second Ttar took him down to nearly half power by himself.
I don't know if just holding will discharge more than one. But for timing purposes, I press&hold three times to release two bars. I just find it awkward to hold for 3+ seconds.
Like others have said usually the damage you take will charge the third bar so you only need to spam a few fast moves to get two bars charged again.