Speech and manner-wise, I feel relatively unaffected by roleplay. Sometimes I might think in the way that N'omiel speaks when I'm going to write stuff online, but that's as far as that goes. It's more of a habit caused from writing a particular way for a character over a long period of time.
Roleplay can effect me emotion-wise, however, which is why I tend to be selective about what character I'm playing.
For example:
Aria Tezari: She was my original character who I had grown heavily attached to. The main reason I decided to kill her off was because roleplaying her had lost its spark; so much had happened to her, and to her family, that I just felt depressed playing her.
Selena Sictor: I have an emotional disconnect with this character, because of a couple reasons. I know how she thinks, and operates, and if I can manage to tap into her emotional side it's enjoyable to roleplay as her. Part of her character traits, however, is that she has a very difficult time trusting and letting in anyone that can see this side of her. She's cold to most people by default, and as such has made no friends. This is the main reason I struggle to roleplay my noble character, because I lack this emotional connect a majority of the time.
Morty Faye: I don't roleplay him much, for similar reasons to why I removed Aria Tezari. He is her twin, and he shares a portion of her extensive backstory (his backstory is approximately 55 paragraphs long). I have kept him, however, as he can be enjoyable to play and because I put so much effort into his application and history. I have to be feeling in a good mood to play him, however, otherwise I may start to feel a little down.
N'omiel M'triche: Initially made as a joke, I wound up creating an app for her and she rapidly became my main character. She's so fun, happy, and cheerful that I just get a great enjoyment out of playing her. She often winds up in situations that can bring a smile to my face, but she also has the necessary backstory to tone the mood down if need be. I have been playing her practically non-stop because this character is just so good at lifting my spirits, which have certainly been taking a beating the past couple months irl.
Mannerisms and behavior? Not so much. Emotions? Definitely.