Seeker

Seekers were guards who, as their name suggested, would search through hiding places, on the suspicion that an Assassin had taken refuge within one.

They were slightly more heavily-armored than a standard guard, though less so than Brutes, and always carried long weapons such as spears and halberds.

Combat
Seekers were extremely intelligent, and would persistently search wagons, wells and piles of hay in an attempt to find hidden Assassins, whether or not they had previously seen one. They often traveled with other lower-ranked soldiers, usually as a pair, or in groups of four.

Upon engaging an enemy in battle, a Seeker could perform both normal and special attacks.

Normal attacks
The Seekers' normal attacks could be blocked using any weapon, however, they could not be countered with any sheath-able weapon or short blade.

Instead, they could only be countered lethally with a heavy weapons, another long weapon carried by Seekers themselves, or a Hidden Blade. The timing for the latter was rather difficult, however, due to the much smaller window of opportunity for the counter.

An attack could also be evaded, or countered through an empty-handed disarm, which could in turn be followed up with a lethal counter-attack with the Seeker's own weapon.

Special attacks
The Seeker's armed special attack, the Sweep, would knock a target to the ground by sweeping their feet out from under them. This did no damage, though it opened up the target to follow-up attacks as they lay on the ground.

The Sweep could not be countered, and needed to be either interrupted or dodged. A Seeker about to perform a Sweep would raise his weapon up and to his right at an approximately 45 degree angle. Ezio Auditore da Firenze could mimic the Seekers, and performed his own Sweep attack. He used two varieties, a short-ranged and long-ranged one, with the latter reaching more enemies in a single swing.

Seekers could also throw sand at their enemies, blinding them momentarily and opening them up for an attack. Similarly to the Sweep, this could be evaded, but not countered.

Special seekers

 * During the final fight with Rodrigo Borgia in the Capella Sistina, he attacks and defends much like a Seeker, though he has far more health. He may even use the Sweep attack characteristic to Seekers.
 * The Farmer, a lieutenant of Girolamo Savonarola during the Bonfire of the Vanities, carries a pitchfork and fights like a Seeker.
 * Certain Papal Guards from Assassin's Creed: Brotherhood fight and are armed similarly to Seekers.
 * The Byzantines Templar faction in Assassin's Creed: Revelations possess a variation on Seekers known as Varangians.

Appearance

 * Seekers are much more common in Brotherhood than in Assassin's Creed II, with many leading patrol groups.
 * In the mission "Infrequent Flier", in the cutscene where Ezio abandons a burning Flying Machine, you can see a Seeker and a Brute on the roof of the Palazzo Ducale. Strangely, these are the only two guards that cannot free-run or climb.
 * In Florence, strangely, the only seekers you can find are Venetian Seekers.
 * In the Brotherhood E3 Trailer, it is possible to see two Seekers using swords.

Combat

 * A disarmed Seeker has roughly the same mobility as an Agile guard.
 * When trying to escape a battle, Seekers will not be the only guards to search nearby hiding spots; all guards will search for you until you have become anonymous again.
 * In Assassin's Creed II, if engaged in a fight with several other guards and a disarmed Seeker, the Seeker will (very rarely) grab Ezio from behind and hold him to allow the others to attack. In Brotherhood, this can be performed by any guard.
 * In Brotherhood, unlike in Assassin's Creed II, Seekers cannot be counter killed with a heavy weapon unless while on a kill streak.
 * In Assassin's Creed II, if you dodge a seeker's Sweep attack, Ezio will use his bracer to break the spear, and force the seeker to use one of the Improvised weapons.