Machine Operators

The Machine Operators is a new Gameplay Mechanic which allow you to hire a new operator/pilot/driver/whatever for your mechanic tower in order to improve its efficiency. You can use your money to hire the new operator, but you won't use money to "upgrade it. Instead, you'll use experience points to train its "skills" instead.

Skills
Each Operator will have 7 Skills, which you can use his/her experience points to learn. His/her experience points are shared with the tower's (e.g. If a tower gains 500 Exp, the Operator will gain 500 Exp too.) In case you don't remember, experience points are gained gradually in a tower's career and is used to unlock upgrades for that tower if it isn't at max level yet.

However, the Operator's experience won't get stacked over time (obviously), but every Operators start with an Exp of 0 and it's like a currency there. Every Operators have 3 Tiers of skills (3 Tier 1 skills, 3 Tier 2 skills and 1 Tier 3 skill), and can only learn a skill from the next tier when ALL the skills of the previous tier have been learnt!

Skills won't change the machine's weaponry most of the time, and EVEN if it DOES change the machine's weaponry, it'd normally be a generic change that should work with most or all upgrades.

Legendary Operators
When there're at least 5 Operators for a kind of machine active at the same time on the screen, you can use a large amount of Exp to replace one of them with a Legendary Operator. The Legendary Operator has all of the Operator's basic skills, but he/she also has a Legendary skill which vastly improves the machine's efficiency, and sometimes there's a sub-ability too! There can only be one Legendary Operator active for a kind of machine at any given time.

There'll be two Legendary Operators for each kind of machine for you to choose, and each of them will have a Preferred Upgrade. If the Operator is using his/her Preferred Upgrade, all of her basic skills (but not Legendary skill) will have 50% more efficiency, and most of the time the upgrade will work better with the Operator's Legendary skill than the other path in a practical sense, too.

If the Legendary Operator's machine is destroyed, he/she won't die, but instead will abandon the machine and fleeing your army, going back to the operators' center, so that you can "buy" him/her again later (This is just for profile purposes, see the next sentence).

Besides, every Legendary Operators will have Proper Names, and may REPAINT your machine to fit his/her need if you're using his/her Preferred Upgrade!

Trivia

 * The Monkey Ace Pilot is the first example of a Machine Operator. If you don't understand the mechanic clearly, you can go there for examples.