- "Tuning the harmonic frequencies has proven much harder than we thought. Every test subject that passes through the portal still returns to us altered"
- ―Head of the Scientist[src]
- Altered, when charging, can easily outrun B.J. with ease, unless he uses Mire. Therefore, it's best to keep maximum range. The first Altered must be killed by forcing him to ram 4 pillars twice. This is done by shooting to provoking him to do it and then putting a pillar between B.J and the rampaging Altered. Note, though, to stand away from the pillar, as the shockwave harms B.J. Also bear in mind that when in the first encounter you finish him and the portal attempts to suck you, a glitch may occur. Instead of being sucked by it to end the level you may be sucked by the floor being trapped under it. To avoid that you will have after you finish him to rise again to the small terrace you start at the beginning of the fight. For the other few Altered encountered, the Leichenfaust 44 is the quickest and easiest way to destroy them: it incinerates them in one shot. Beware when engaging the Altered in the Hospital, Geists are quite aggressive there since it is the only weapon that can destroy him.
Altered are found in mercifully few levels, perhaps the least encountered enemy with boss battles. One is first encountered in the Hospital mission which is the only time it is fought as a boss where as later times in the game they are just enemies that can be easily defeated. They are the only enemy that other enemies also attack due to them not being able to control the beasts.
Altered throw rocks or part of bodies when bodies are next to him, and so, drop nothing.
- They bear a strong resemblance to the Tank from Left 4 Dead except it cannot be killed without a Special Weapon.
- Although the boss battle in Hospital is supposed to done by luring the Altered to destroy four pillars supporting the portal, but if player has Leichenfaust 44 (accessed by enabling cheats or trainers), just one well-placed shot at the pillars can win the fight.
|Humans||Drache Trooper · Elite Guard · Heavy Trooper · Rocket Trooper · Scribe · Soldier (Wehrmacht · Sniper · SS) · Wolfgang Statz · Veil Assassin|
|Creatures||Despoiled · Geist · Sniffer|
|Machines||Keiler · MG42 · Portable shield · Tiger tank|
|Bosses||Altered · Viktor Zetta · Queen Geist · Hans Grosse|