A science hero was not born with superpowers, but acquired them at some stage in life. Often this involved an accident or exposure to some unusual phenomena, commonly involving mutagens or weird radiation.
As a science hero, you can have any set of powers imaginable.
There is little difference between the science and mutation origins. Both have access to mysterious powers, only science heroes got their powers during their lifetimes and have a pre-super life to fall back on. This colors their outlook and relationships.
Science heroes tend to have Cyber, Pulp, Sorcery, and Super schticks.
Science Origin in City of Heroes
Science villains exist in amazing numbers. There are more or less reliable methods of creating supers - best exemplified by the villain contacts Dmitri Krylov and Doctor Creed. Several groups replicate themselves this way.
Trolls
Perhaps the most basic and archetypal science heroes; trolls are humans who have used too much superadine. They develop a superhuman level of strength and endurance, but become brutish and ugly enough to be cast out of society at large.
Council / 5th Column
The Council/5th column is supposed to be mutants, but this does not make sense; their officers and higher-ranking goons receive super-soldier treatments, and their vampires and war wolves are made, not born. Galaxies are also made, by nictus infusion. The Council also dabbles in both technology and a little magic, while their lower-ranking goons are just trained naturals. Still, science is definitely their main origin.
Devouring Earth
These almost transcend science and become magic; animated rocks and plants that have never been human are at the very limit of what the science origin can do.
Clockwork
Powered by a psychic resonance network created by a single mastermind also borders on the limits of science; the original Clockwork King was probably a Mutant that used Technology to improve himself; his creations are built like technological robots, but their technology makes no sense.
Contaminated and Arachnids
A by-product of Arachnos super-soldier experiments, these unfortunates are rejects, leftovers, and victims of environmental contamination.
Lost
As mentioned under the Alien origin, the Rikti used scientific means to toughen themselves; the Lost are humans that are part-way through the same process.
Vazhilok
Classic reanimator zombies, doctors and orderlies using weird science (but themselves natural), and Eidolons that are the result of a successful super-human medical process.