Bill Ferny is the filthy spy from Bree who serves Isengard for money. He is one of the two rogues of Isengard's heroes, meant for espionage, scouting, and vandalism, rather than for combat. As this implies, he isn't really good at combat, but he has some good abilities that can really help the faction in the early game, that he will earn if you pay him gold, eventually taking matters into his own hands and becoming a good fighter for a short period of time.
Level 1: Bribing - Bill Ferny bribes the workers of an enemy resource building, which causes them to spy for him and reveal the nearby area for 90 seconds. They will also give a small amount of resources to Bill Ferny. Left click on an enemy resource building.
Level 1: Disguise - Bill disguises himself as the chosen unit so he may spy on the enemy. Bill can be revealed through enemies' reveal abilities, if he attacks, or if he uses abilities. Left click on desired units.
Saboteur Service: Disinformation (Costs 100) - Bill sends false information to an enemy hero or building. The hero or building loses its vision for 30 seconds. Left click on target hero or building.
Information Service: Snitch (Costs 200) - The spy of Isengard has his snitches everywhere and therefore knows many of his foe's secrets. For a short amount of time, the closest enemy hero will be revealed. Left click to activate.
Head Money: Cutpurse (Costs 300) - Bill Ferny is a trained thief and pickpocket. For a short time, Bill Ferny deals +35% damage, has +50% armor, +20% movement speed and steals 40 resources with every hit on a hero or unit. Left click to activate.
Bill Ferny can purchase 3 upgrades which each increase his level by 3 and unlocks a new ability. These are the upgrades you can research:
- Saboteur Services (100): Unlock the Disinformation ability.
- Information Service (200): Unlocks the Snitch ability.
- Head Money (300): Unlocks the Cutpurse ability.
Bill Ferny is one of the first choices among the hero units of Isengard when the game begins, as his role is a combination of rogue and raid leader. While he is the weakest hero of Isengard combat-wise, he shows his strength most in the early game as you continue to pay him to unlock his new abilities. In total, it will cost you 600 resources to bump Bill up to snuff, since he actually gains experience points quite slowly.
This hero is more or less useful for spying on the enemy, and becomes increasingly effective at his job as he levels up. He can bribe enemy resource buildings, such as their lone outposts, disguise himself as nearly anything to move undetected through enemy territory, and can even shut down a building's line of sight to allow your forces to pass through undetected. At his maximum level, Bill Ferny gains a useful ability that makes him much better at fighting enemy units when he gets cornered, and it also allows him to earn you a lot of resources as he fights, improving the wages trickling into your coffers.
While his services are invaluable in the early game when you're strapping for resources, his strength comparatively weans as time goes on, when you have access to stronger heroes and have to fight against stronger enemies. In the mid-to-late game, Bill Ferny becomes expendable, as his ability to disrupt enemy infrastructure pales in comparison to the building-destroyers such as Wulfgar or any of your siege weapons.
There is a hilarious fact about Bill Ferny which is he can disguise himself as anything: For eg. when Eärendil's boat Vingilot is summoned by Lothlorien, he can even disguise himself as that!