The Plaintiff is XYZ.LP which I believe is a limited partnership. We believe this to be a fictional company as the California Secretary of State Office has no record of them.
I assume "XYZ.LP" is a made up name. I also assume that the entity listed as the plaintiff actually has "LP" at the end of its name, and that's why you believe it to be a limited partnership. Am I correct about that? If so, does the plaintiff's name match the name of the landlord on your friend's lease (if there is a lease)? Also, the CASOS search engine can be a bit persnickety, so make sure you have the entity name spelled correctly. If the entity name has initials, you should try them both smushed together and separated (e.g., "A.B.C." and "A. B. C."). You should also only search the name without the "LP" designator.
Is it possible to for an attorney to file an unlawful detainer on-line with the County Clerks (San Mateo County) and not have the Plaintiff be a real person or corporation?
Of course it's
possible, but I doubt that's what you intended to ask.
If, in fact, the entity is a limited partnership and has not properly qualified to do business in the state of California, then your friend may want to file a demurrer.
they know that the person that they are attempting to evict is not a tenant and has never paid rent.
The friend has lived there for over 30 years.
If your friend has lived there for over 30 years and doesn't have an ownership interest, then he/she most certainly is a tenant.
The friend is a dumba... and proceeded to pay mortgage, taxes, insurance and all expenses going forward believing that the owner had transferred the property to them.
Please don't use "they" and "them" unless you're referring to multiple people; it makes what you write ambiguous. Your friend is either "he/him" or "she/her," but it would be best simply to refer to him/her as "my friend." The landlord, if an LP, is "it," but "the landlord" or "the owner" would be the best way to avoid ambiguity.
That said, on what basis did your friend believe that the owner had transferred ownership of the property to him/her? Is there a deed of any sort (whether or not recorded) by which the owner of the property transferred title to your friend?
30 years later the owner transfers the title via quitclaim to his buddy in this ficticious name.
So, 30+ years ago, "Joe Blow" bought the property and allowed your friend to live in the property. Your friend, instead of paying rent, paid the mortgage on the property. Then, after the mortgage was paid off, Joe transferred ownership to "John Smith." Is that the deal? What is the connection between Joe and/or John and the LP that is the plaintiff in the UD case?
The friend files a civil fraud case against the owner which is in process now.
Which owner? Joe or John? What's the basis of the fraud claim? Is your friend represented by a lawyer? If not, he needs one if he wants any chance of succeeding in what he's doing.