Throughout the first six Star Wars Skywalker Family Saga Films, viewers understanding of the Dark Side primarily relied on the philosophical beliefs of Emperor Palpatine/Darth Sidious, a Sith Lord who seeks to dismantle the New Republic & the Jedi in order to control the Galaxy.
Often his method of philosophy relied on pitting his proteges or understudies against each other, in order to always have the best apprentice (by his standards). One primary example in the films is when Anakin is aided by Palpatine to not give mercy, but instead to kill his current Sith apprentice, Count Dooku/Darth Tyranus and have Anakin take his place. (Revenge of the Sith)
In addition, Darth Sidious always then seemed to have back-up plans, such as having Dr. Cylo create force-mimicking genetically-modified human-cyborgs take on Vader after the fall of the first Death Star, in which Vader easily defeats Cylo's creations (2015 Darth Vader Comics). Or Operation: Cinder as means to destroy and rebuild his empire, in case of unexpectedly reaching his demise.
Now it seems like Sidious was trying to stay alive and in control for as long as possible, but never without realizing he could die!
So my question is, despite having plans, and wanting or believing in always having an apprentice (and considering Anakin was "The Chosen One" ), did Darth Sidious ever intend or anticipate that Darth Vader would eventually take his place?
Other things to consider:
- Dr. Cylo can transfer his conscious to other bodies (New EU is playing with Life Extension).
- The name Cylo seems like no coincidence to the name Kylo, a name given to Ben Solo by Snoke.
- By the end of The Last Jedi, Kylo Ren becomes
the leader of The New Order and we know Snoke invested in Ben Solo, because Snoke believes in the power of the blood line.
- In The Force Awakens, Kylo Ren tells the helmet of Darth Vader, belieiving he is communicating with his grandfather, Darth Vader, that he "will finish what Darth Vader had started.".
- Sidious even allegedly murdered his own former master, Darth Pleagus the Wise, in his sleep.
- Aftermath Trilogy reveals Operation Cinder went beyond The Empire's Destruction:
The events of the 2017 novel Aftermath: Empire's End, written by Chuck Wendig, revealed that Operation: Cinder was part of a greater Contingency devised by Emperor Palpatine to destroy the Empire and its adversaries so that it could begin again. http://starwars.wikia.com/wiki/Operation:_Cinder