Watch dog is my #2 because of his dps on most attack. I used to get one-shotted by most of these bosses. with health max at 1/2 that is 950. I put on 5% all damage reduction and 7% physical reduction damage runes on. Plus attire that has best resistance. I don't care for fashionborne, I wear simon harrow and bone ash since they have the best stat for certain bosses. What wre 1 shot, are now I maybe have 1-10% left, enough to heal. That lets you have some mistakes. Grant a direct hit, if you don't move, is a one shot. Amy jump and watch dog charge are not one-shot like the pig charge ram (of all the bosses the pig can still 1 shot you when you enter). Ok watch dog has a one-shot move, when he jumps into the air toward and lands on you. This is rare but it happens a few times when it is low on health but is dodgeable. Like how amy will shoot 3 rounds of laser and jump on you, 3 times when she is low health.
After watching the video again I think ebietas may be have more moveset, but you hardly see them because you are so small and all you see are her thigh. I jumped thru her once, not sure how. Her call of beyond went thru her, since i was hiding in her back and got me. Crazy camera, but I got used to it. while Amy is the hardest (time wise) for me, I like it. I like fighting the descendant because it is a human boss, you can gun parry him. As with the keeper, but she is slower (she has the shoulder fire hit that is powerful).