In this task, you're expected to write answers to questions involving multiple references to the same entity. The answer to the question should be unambiguous and a phrase in the paragraph. Most questions can have only one correct answer.

Let me give you an example: Passage: Nearing London, Oliver encounters Jack Dawkins, a pickpocket more commonly known by the nickname the "Artful Dodger", and his sidekick, a boy of a humorous nature named Charley Bates, but Oliver's innocent and trusting nature fails to see any dishonesty in their actions. The Dodger provides Oliver with a free meal and tells him of a gentleman in London who will "give him lodgings for nothing, and never ask for change". Grateful for the unexpected assistance, Oliver follows the Dodger to the "old gentleman's" residence. In this way Oliver unwittingly falls in with an infamous Jewish criminal known as Fagin, the gentleman of whom the Artful Dodger spoke. Ensnared, Oliver lives with Fagin and his gang of juvenile pickpockets in their lair at Saffron Hill for some time, unaware of their criminal occupations. He believes they make wallets and handkerchiefs.
Question: Who believes Fagin's gang make wallets and handkerchiefs?
The answer to this example can be: Oliver.
Here is why: In the sentence "He believes they make wallets and handkerchiefs", the pronoun "he" refers to name "Oliver".

OK. solve this:
Passage: In 17,000 B.C., the Seven Primes travel across the universe to create Energon with star-absorbing machines called Sun Harvesters, which destroy stars in order to collect their raw material. One of them defies the rule to never to destroy a planet with life by establishing a Sun Harvester on Earth, earning him the name "The Fallen". The Fallen is confronted by the other Primes, who imprison him before he can harvest the Sun using the Matrix of Leadership. The rest of the Primes then sacrifice themselves to hide the Matrix in an unknown location.
In the present, two years after the events of the first film, the Autobots and the U.S. military have formed the Non-biological Extraterrestrial Species Treaty, a classified international task force used to eliminate the surviving Decepticons. In Shanghai, the Autobots intercept two Decepticons, Demolisher and Sideways. Sideways is killed by the Autobot Sideswipe, while Optimus Prime kills Demolisher, but not before he warns them of the Fallen's return. At NEST's secure headquarters in Diego Garcia, National Security Adviser Theodore Galloway concludes that since Megatron's corpse is at the bottom of the Laurentian Abyss and the last-known AllSpark shard is secured in the base, the Decepticons must still be on Earth solely to hunt the Autobots. The Decepticon Soundwave hacks into a military satellite, overhears this information, and sends Ravage to retrieve the shard.
Question: What is the name of the character who warned the others about the Fallen's return?
Answer:
Sideways.