The builder
Six steps: appearance, personality, voice, background, the way it speaks to you, and what it should never bring up. That last step is rarer than it sounds and it is the reason a character built here drifts less than one built elsewhere.
Memory per character
Memory is attached to the character rather than to your account. Build three companions and they each remember their own history with you, which sounds obvious and is not what most of the category does.
What is missing
No native apps, and the price is not published until you sign up — we do not list a figure here for that reason. For a category where the monthly cost is the main decision, that is a real mark against it.