Below info and Theory will not be a plausible,most of people will click unlikely . This is somerthing very expected , though it should be like that, because best theory is the  one most schocking and the most unexpected one, it is naturel to see lots of unlikely so, most of people's mind is very basic 

Ultimate Approach to Create Best Satisfactory Theory and Ending

To do 

1- Forget about analyzing all clues one by one ,see them all together in your mind and see big picture
2-Do not consider only clues given in serial , but consider sprit of serial (Use deductive method,look all serial holistically, do not ever listen any clue like physical appearence, voice etc. 

3-Do not forget all serials will make contract with TV channel just for one season ,if ratings go well than new seasons may take place .So Producers of this serial(Bruno Heller) were actually planning to make just a simple " Smart Dedective- Obssessed Serial Killer" chase. But stuff got expended and they had to extend story by making a sensible connection with pre-defined Character of serial killer(He has to be powerfull, great network ,everywhere at same time). 

   3.1 So Do not ever expect something from an episode fully matching with previous episodes. Remember season 1 there were a different Jane and very stupid episodes, like where jane was hypnotising people, do you remember the episode where Rigsby hypnotized.Those were stupid just enjoying purposed episodes.

  3.2 Everything coming in future episodes are purposing making the serial with a great ending, because great expectation.

4- Everything depends on RJ - See the spirit of Serial

This serial based on the character RJ , not Jane. All power , all mystery,all reason of ratings are dependent on two emotions; 

  1- RJ (More clever than a Mentalist like Jane),unreachable, doing whatever he wanted,controlliing everything

  2-PJ (Emotionnaly broken, fully clever) 

Audience want PJ to reach RJ ,but the fact is audience wandering about RJ and they want to test this if PJ can be able to break RJ ,the struggle of PJ and the ultimate power RJ ,only these two are the essence of interest to this serial

  So spirit of serial requires to make RJ ultimate power symbol and PJ is the struggling one to break this power,ending has to carry this sprit.


4- CBS Channel is a a channel belonging to masonic organization called illuminati. Check the season 5x24 ,you will see a lot of one-eye pyramids symbolism. Even ,intro of each episode you first see half face of Jane, One-eye symbolizm.

Start to Analysis

Purposes: 

1-Keep Rj , most powerful, most mysterious
2-Make things explainable from previous seasons and episodes,cover everything all clues given , all pyhsical description given etc. 
3-Kepp PJ strugglin one ,but do not kill audience small expectation possiblity a defeat of RJ by PJ

Best Theory and Ending 

Consider all above ,this is the biggest picture what producers are going to connect all ; 

There is a secret society that RJ is managing, a dirty satanic /demonic organization. 
This organization is above police ,homeland security etc department. But it is so powerfull that ,there is a sub-organization inside CBI, FBI 

Everyone in this society is knowing RJ as master. And there is an hyrearcy between people, so there is decades of Red Johns, from organization making killings, but using same voice . So blind girl will define RJ different, someone else will define it different. Lorelei will say you shaken hand with thim, but how can we sure these girls met same person and original RJ ???  SO there is more than one person disquising RJ with permission from RJ's organization.

Jane will discover this society within Police departments firstly, than he will find out how this society is great and visualize is an antagonist organization against RJ's organization, PJ will cover also this in late ly coming episodes. 

Visualize and his leader will help to catch PJ to RJ ,but will not be enough, cause RJ will be connected by satan/demon himself.(Because of CBC Channels' masonic symbolism purposes)

Conclusion

1- RJ has never been shown off before
2- RJ is not someone from the list
3-RJ will be a person not fitting with any description given