Sevati as a lee is actually quite adorable. It's hard to surprise her, it really is since she's always aware of her surroundings and has the reflexes of a cat. You can try your best to tickle her, but she'll always thwart your attempts. If you want to get her, you need to gain her trust and be close to her. It also helps if she knows you're a playful person in general. That way she knows you're not a threat to her and will let you a little closer to her. Besides, she might get a little sneaky herself and poke you here and there to get a reaction out of you. It's fun to her to see you jolt and squeak like that. If she can surprise you like that? All the better. And yes, she probably does expect you to want to get your revenge on her eventually. Your best bet is to just approach her, wait until she looks somewhere else, and then go for it.
Squeeze her sides, she's gonna double over a little and squeak herself. If you're strong enough, you can catch her hands, hold her wrists in one hand and then go to town. If you tickle her sides for long enough, she'll eventually topple over and fall to the ground. Although she may try to fight back, she does go weak when being tickled, especially if you drill your fingers into her ribs. Her weak spots do include her sides, ribs and knees. Though, she does cuss you out a lot when you tickle her. Expect her to thrash around as well. She doesn't mind it as much since it's you, someone she trusts, but still. It's humiliating to be in a position like this since she much prefers to be seen as this strong and reliable woman. But if you scratch behind her knee and her ribs, all her composure goes out the window and she simply curls up.
I do think she's immune to most teases. If you tell her about how ticklish she is, she'll just tell you to shut the fuck up. Even before the tickling commences, she doesn't react much. For the most part, it just gives her ideas. And if she's out for blood? You're fucked. But anyway, if you call her laugh cute and coo over it, she would see it as a genuine compliment, even if she's trying her hardest to get away from you. Her laugh is really cute too. It's a little higher pitched than it normally would be, even her giggles are, but it's adorable. I don't think she tries too hard to hold back her giggles, she's more focused on trying to get away from you. Raspberries don't work too well on her, though. She just thinks the noise they make is stupid and it's just not as effective as your fingers. She is feather ticklish, though. Brush a feather behind her ears or over her neck and she'll scrunch up, giggle, and move away from you. One of the reasons she prefers short hair normally is because longer hair tickles her neck. She only really uses her wigs when she's on a mission.
She's vengeful, though. Beware of her. But as long as you don't tickle her too hard, you should be alright. She can take someone rougher, but if you stay gentle, innocent and playful enough with her, she won't take too much offense on everything. If it's just you wanting to goof around a little, then all is good. You wanna see who's stronger? Be prepared for a tickle war that will last days! It's kind of fun, though, when she does let loose a little bit.