This is superficially similar to the plot of the graphic novel Watchmen.
Spoilers for the graphic novel, and some for the movie ahead and unmarked. The spoilers make up a substantial amount of this answer, and thus are not marked.
The main antagonist of Watchmen, Ozymandias (Adrian Veidt) plans to save the world by giving the world an external threat to prepare against. In the graphic novel, this threat is a supposed race of aliens, of which an initial 'invader' resembles an alien squid.
To this end, he collects a large number of artists, designers, writers, etc on an island. They are all hired in secret and sign NDAs that prevent them from discussing their new project, then 'disappear' completely voluntarily. They are pampered and treated well, and spend quite a while (up to and including a year, if I recall) working in secret. These creative people were responsible for developing the entirety of an alien species, from biological and sociological details to their history, mythology, aesthetics, and plans. These writers and creators, primarily from horror genres, are told this is part of a massive horror project which will redefine the genre, and all participate enthusiastically.
When they have completed their work, Adrian eliminates them all.
Adrian loads all of the information these artists have created into the created mind of a genetically-engineered creature that resembles one of the species the artists developed. This creature has a brain that contains enormous psychic potential. The creature plan is for the creature to then be teleported into the middle of New York, using a device Adrian's company has been developing in secret. The teleporter is known to be ineffective, killing the teleported subject on arrival. The squid is engineered such that on its death it will send out a psychic shock that will kill huge amounts of nearby people and be felt by those who are psychicly sensitive around the world. Those who are sensitive will also receive portions of the knowledge uploaded to the squid.
Adrian's plan is for this to appear to be the first step in an invasion plan, only for the alien's teleportation to have unexpectedly failed and killed the initial invader. The knowledge sent out 'by accident' upon the invader's death would be spread across the globe, ensuring that all governments received independent confirmation of the data. Adrian's plan was for this to give the governments an exterior foe to focus on.
Some of his old allies (the protagonists of the comic) pieces most of this together over the book, and Adrian - seemingly in traditional supervillain fashion - helpfully fills in the rest of the plan for them when they confront him in his base (where he has just finished killing the scientists and researchers who helped him develop the genetic, psychic, and teleportation technologies).
The protagonists declare that they will stop him, leading to one of the most iconic panels in comic history.
This meets most of the criteria in the question - the scientists and researchers working for Veidt were eliminated after they succeeded (as were the artists and writers who worked on other parts of the project), the 'villain' did create a biological weapon (the squid) to attack a city, and the goal was for the governments of the world to have a new, external, existential threat to focus on.