(Played by Tom Hardy)
The Reman Praetor Shinzon was a clone of Jean-Luc Picard. Shinzon was a product of a failed experiment to clone Picard and send the clone to infiltrate Starfleet, with the intent to defeat the Federation from the inside-out. But instead of serving the Romulan Empire proudly, Shinzon was banished to Remus, where he became a sort of "leader" to the Remans, who up until that time lived (literally) in the shadow of Romulus.
Shinzon, using a thalaron-based weapon, effectively took over the Romulan Senate and started a series of events leading up to an ultimate end-game between him and Picard. Shinzon lured Picard and the Enterprise-E to the Romulan Neutral Zone by using the B-4 android as bait. Once there, Shinzon engaged the Enterprise with his massive warship, the Scimitar, a vessel armed with 47 disruptor banks that could fire while cloaked.
Shinzon suffered from an accelerated metabolism as a result of his genetic engineering. He also possessed a unique telepathy which, with the help of his Viceroy, he channeled to violate Counsellor Troi's thoughts.
Ulitmately, Shinzon died in a final confrontation with Picard, his source material, after being speared by a broken-off shard of his own vessel. Refusing to give up, using his last ounce of vengeful will, Shinzon inched his way down the "spear" he was impaled upon, and died with his hands around Picard's throat.