Shinra has fan clubs for SOLDIER First Class “Heroes”. Each of the prominent SOLDIER First Class members has one.

• Angeal has Keepers of Honor
• Sephiroth has Silver Elite
• Genesis has two: Red Leather, the Loveless Study Group

Later on in Crisis Core: Final Fantasy VII, Zack can actually gain fans for his own fan club. He has to “defeat 30 enemies in the Junon Perimeter defense after defeating General’s Tank”, saving the inhabitants. This action impresses the residents and causing Cissnei to gather news on Zack’s personal life, under the pseudonym “Black Suit”. In this sense, he finally achieves his dream of becoming a hero.

But what makes a hero? According to Shinra, it’s helping Shinra realize their goal of global domination. Sephiroth maintains spotlight as a celebrity war hero and the poster boy for both the Shinra Military and the company’s SOLDIER program, influencing both Genesis and Cloud in the process.

While reporters focus Wutai War news coverage on Sephiroth, Zack aids the corporation in achieving their goals.

Force multiplication, in military usage, refers to an attribute or a combination of attributes that dramatically increases (hence “multiplies”) the effectiveness of an item or group, giving a given number of troops (or other personnel) or weapons (or other hardware) the ability to accomplish greater things than without it. The expected size increase required to have the same effect without that advantage is the multiplication factor.

As we can see in the game, from the Final Fantasy Wikia:

Sephiroth joined SOLDIER, and during Wutai War was instrumental in ensuring Shinra’s dominance.

That’s exactly how Sephiroth was used, and what Zack became. Both aided Shinra in their conquest of Wutai.

Force Multipliers are tools that help you amplify your effort to produce more output. A hammer is a force multiplier. But what happens when a human being is used as a tool? We see this time and time again when those in the service are pushed to their brink and end up “snapping”, or suffering PTSD. And this has happened with Sephiroth. But some people don’t snap. That’s when they still become useful to their respective organizations.

Zack clears Midgar of dangerous monsters, increasing development for the Urban Development team. He charts into unidentified territories, clearing the way for Shinra to exploit the land. He aids Shinra’s quest for new Materia and items. He crushed Shinra’s competition. He helps Shinra grunts train. He destroys the forces of Wutai and Genesis. He hunts down craftsmen for Shinra. He tames Summon monsters. He finds an abundance of Mako stones, aiding to the mass production of Materia.

Zack manages to take out any obstacle to Shinra’s goals, which is a big reason the corporation is so powerful. Powerful enough to kill him in the end.