This would pretty much be a fist fight? Alpha fights with a sword, but you get what i mean.
Alpha wears a slime body suit, which she forms weapons such as swords out of, she can also make a weapon out of any part of it, ie if someone snuck up behind her, she can make a sword come out of her back.
She can cause fear with a gaze, dodge things on instinct etc, but that's really relevant here, what i am curious about is Mori's sensing ability cause Alpha does abuse her stealth in combat, while fighting someone who was focused on her, he completely lost sight of her, she sneaked up on him with no bloodlust or sound.
In terms of fighting skill, all members of Shadow Garden are taught in
Cid's martial which is a combo of countless other martial arts, and is on a level where centuries of training can't reach, that said not everyone has the same level of mastery over it,
Beta would be the one who is most skilled in terms of martial arts as she has most accurately replicated Cid's style.
Though Alpha is still the strongest of the 7 Shadows, so she does have a good degree of mastery, and makes up for her short comings with magic. With magic she can also turns herself into mist that covers the area, she can also sense everything the mist touches, and attack basically from random/unpredictable angles while in that form, i am talking to the point that even Cid who has precog and info analysis couldn't deal with it, and had to basically brute form his way out by blowing away all the mist.