The defense of Waterloo [G&B]

The plague, and all those infected, can be stopped by a crucifix, and they have an irrational fear of the Holy Trinity. This is because the undead are all those souls of the deceased who never repented of their sins and constantly rejected God. For this reason, they are stopped and stunned by a crucifix or other Christian symbols. Only chaplains, priests, or simply people of blind faith similar to those mentioned above can stop the plague with their crosses or crucifixes. Cannibals will do everything they can to avoid seeing the symbol, covering their eyes or becoming frightened as if they were seeing a bright light. Meanwhile, the exorcism crucifix directly destroys the soul of the cannibals, being able to kill them by exorcising their sinful souls. Its effect is to slow down the cannibals and progressively damage them.

The next infected type is the Cuirassier, or Cuirassier. These were heavy cavalry soldiers before becoming infected. They are the infected type who can remember the most before dying, possessing advanced swordsmanship skills and the ability to block sword strikes with their own heavy saber. Physically, part of their face is disfigured, and they have black eyes, one with a red glint. Their right arm, where they carry their sword, is malformed, appearing to fuse with the weapon—a grotesque sight. Recently infected cuirassiers do not suffer from this. A cuirassier's uniform varies by nation, but they always wear their cuirass and a steel helmet, which are very effective against melee attacks. The only recorded variant of a cuirassier is the Life Guard. These are heavy cavalry soldiers from the British 1st Life Guards Regiment. They wear a gold and black helmet befitting the regiment, a red coat, gray trousers, and black boots worn beneath the trousers. However, being a British Trooper, he doesn't have the armor, as British military doctrine at the time didn't use it. The Viral Runner is the next infected type, appearing only when a person is very recently infected—less than 30 minutes after becoming infected. They are very similar to the Runner, but their red eyes have a noticeable trail of the same color. They are very dangerous, as they are as resilient as a Shambler, but they infect more lethally, either by vomiting on their victim or by repeatedly scratching them. These scratches don't directly infect. The Viral Zapper is like the Zapper, but it has a trail in its eyes when it moves, just like the Viral Runner. This occurs when a human Zapper is very recently infected; it is faster and more aggressive than a normal Zapper. Neither of these Viral types generates naturally in this scenario; they only appear when a soldier falls to the infection.

The next type of infected is the Zapper. Before becoming infected, they were ordinary soldiers, often fulfilling the role of sapper, as the name suggests. These soldiers were a mix between infantry and engineer. Their tasks typically included setting up and dismantling camps, or breaching barricades that the regiment couldn't pass through. They wear a military uniform, depending on the regiment they belonged to before falling, though it's worn and dirty. The Zapper usually carries an axe, which they use to attack. Even as an undead, they still remember how to use it. Physically, they are like all other undead, with unhealthy grayish skin and glowing yellow eyes. The Zapper is slow, slower than a Shambler, but their axe swing will inflict significant damage if not dodged.
The next infected is the Bomber. Physically identical to a Shambler, but carrying a torch and a barrel of gunpowder, its job before infection likely involved carrying these barrels to demolish mines or assisting with supply deliveries. Its attack method is simply to approach and ignite its barrel, causing a dangerous gunpowder explosion.
If you back away, shooting him is an option; that would completely neutralize him.
The next infected is the Igniter. This undead creature has extremely emaciated skin, burned and charred, yet somehow still stands. Its clothing is also that of a civilian or worker, suggesting it was a lamplighter before becoming infected. Its method of attack is simply throwing its lamp and shattering it on the ground, causing a fire in that area. After using up the lamp, it will no longer be able to do this.

The plague is the disease that has struck Europe. It is a disease that initially appeared among the Ottoman Janissaries, who began to die after a period of illness. The disease first appeared at the end of the Russo-Turkish War. This disease had a high mortality rate of 99%. When it reached Russia with soldiers returning home from the war, the government tried to conceal it as a simple illness. However, it wasn't until Napoleon's invasion of Russia that things changed; after the burning of Moscow, the dead officially began to walk the earth. This plague is spread through bites, or through glucose and blood via vomit by viral carriers.
There are several types of undead that the plague produces: The most common is the shambler, an infected individual who has been in the plague for at least one or two hours. They have unhealthy, grayish skin and wear normal clothing from that era. The vast majority are fallen civilians, but there are a few fallen soldiers. The shambler is a relatively slow undead, to the point of being easily overtaken by someone simply walking. Alone, they are not a great danger if one has a weapon, but without it, they possess enough strength to match a sailor of the time, who were already strong in their own right.
Their method of attack is either by scratching or by struggling to try to bite the victim's neck and infect it. As mentioned, they are not a problem on their own, but they do not usually appear alone; they are almost always in hordes.
Runner: Very recently infected, less than half an hour after becoming infected. They look very similar to Shamblers, but are much more aggressive and faster, to the point that running is not an option. Although relatively fragile, their strength is high, capable of knocking their victim to the ground. Then, during the struggle, they will try to bite their neck. What differentiates the Runner from the Shambler is that the Runner has glowing eyes.

They are the backbone of every army. They possess the largest number of regiments for this very reason. They focus on fighting in columns and firing volleys to maximize firepower and compensate for the slow reloading of the flintlock musket that all privates carry. After firing, if they have to engage in close combat, the privates will use their bayonets attached to their muskets. Regular privates only carry this for greater historical accuracy; not everyone could afford a saber at the time. Beyond line and volley tactics, there are skirmishes and sieges, both defensively and offensively. In defense, they often use the advantage of height provided by walls, etc., which would be very useful against threats.
The officers are responsible for keeping the regiment in order and guiding it.
The ranks are organized as follows, from lowest to highest:
Second Lieutenant
Lieutenant
Captain
Elderly
Lieutenant colonel
Colonel
Brigadier general
Major General
Marshal.
All these ranks are attained through merit, leadership ability, etc. However, in the unique case of the British Army, there is a system of purchasing commissions. Without purchasing commissions, one can only obtain "non-commissioned" ranks such as Corporal and Sergeant, which vary between different branches of the armed forces.

The story is set in June 1815. Therefore, everything will be set and adapted to reflect the 19th century, including ways of thinking, housing, clothing, architecture, and military tactics.
For this reason, the armament cannot be older than in the year 1815.
The most commonly used weapon by armies would be the matchlock musket; the model varies by nation, such as the Brown Bess for the United Kingdom, or the Charleville for France, etc.
Other available weapons include sabers, such as the infantry saber for officers, the briquet for elite troops or marksmen, the cavalry saber (light or heavy), the cutlass (also known as the boarding saber) for naval officers, etc. Axes, whether for work or fighting, are also completely permitted.