A guide on some of the most useful tips a Phoenix Point player needs to know about certain enemy weaknesses.
Tips to Fight
The Right to Break Arms
Certain enemies, predominantly humans and some species of arthron, have a glaring weakness that is easy to exploit: Their right arm.
You'll notice when hovering over the majority of weapons in the game that they specify that two arms are needed to use them. Some exceptions to this are handguns, all melee weapons, and grenades.
This doesn't just apply to your units, however. If you fire a shot at the arm of an enemy and that shot breaks their arm, they can no longer use two-handed weapons. The grand majority of human enemies in the game have only one weapon in their inventory, and when this is a two handed weapon, breaking their arm renders them irrevocably demilitarised.
When an enemy has their arm broken, they will either fight on with whatever equipment they can still use (back mounted rocket launchers, spitter heads, etc) or run for the nearest map edge to evacuate.
It is, in the majority of situations, a lot easier to break an enemy's arm than to knock their entire HP bar down. One basic sniper with a clear shot can break the arm of the strongest human enemies in the entire game, as their exists no suit of armour which provides enough defence to stop a direct hit sniper bullet from breaking a human arm. The same is true of the arthron sub-species which relies on their claw/machine gun arm for damage (i.e., they have no spitter head and their left arm is either a shield or has no equipment).
This method is (almost) fool-proof, but some exceptions are worth baring in mind. While basic medkits do NOT repair broken limbs, other healing methods can, so be on lookout. This also does not work on enemies which regenerate, UNLESS you disable the body part which provides this regenerative effect before-hand, but if you can both break their torso AND their arm, you could probably just kill them without needing to use this tactic. This is why this method is less useful against Triton type enemies, as many of them regenerate.
One other fun benefit of this tactic is that is prevents an enemy with the return fire ability from, well, returning fire, allowing you to use even non-sniper type units such as assaults to disable the arm (right or left) of an enemy assault-class human or machine gun toting arthron.
Shock and Flaw
Three types of enemy are very, very vulnerable to a certain weapon: the Neurazer. This melee weapon can be used by any Phoenix operative regardless of class, and costs one action point to "fire", dealing 7 paralysis damage and 10 HP damage to all but the most heavily armoured enemies.
The three enemies that are weakest to this are enemy snipers (without handguns), enemy heavys, and Chirons that don't have legs which are capable of melee attacks. This is because firing a shot with a sniper rifle, a heavy weapon or the Chiron's back mounted catapult thingy requires three action points to use, and paralysis removes total action points proportional to the percentage of current paralysis to total paralysis for the given unit.
To put this in simple language, if an enemy has, say, 30 strength, then it can "house" 30 paralysis points before if becomes total paralysed. However, with each 25% lost towards this total, one action point is taken away, of the four that each unit has. This means that raising an enemy's paralysis will gradually render it unable to use more action point intensive weaponry, until it eventually cannot act at all.
Because the Neurazer cannot miss, this takes the aiming out of removing threats from the battlefield. Because the game ends a mission when all remaining living enemies are full paralysed, this means that you can, theoretically, win a mission with nothing but neurazers. Because any pandorans that end the mission fully paralysed are added to your pandoran storage, this means you will have a steady supply of fresh food and mutagens from all those Chirons.
Why bother cutting through their massive HP pool when you can cut them into burgers back at base?
The strongest late-game character build, in my humble opinion, is what I like to call the "Whack-a-moler". In order to create a whack-a-moler, you have to get your hands on a high damage melee weapon (mattock of the ancients is the best for damage but Marduk's fist is the easiest good one to acquire) and also the tier three robotic augmentation blueprints. You'll also need to have a priest who can apply frenzy (or failing that, a frenzy applying item).
Here's it works: You get either an assault or a heavy and give them the other class to make them an assault/heavy hybrid class. You give them the heavy's brawler and inspire abilities, the assault's rapid clearance and dash abilities, and as much speed as possible (this means light armour, too). Then, you augment their torso into the Vengeance torso, the one the gives proficiency with melee weapons and allows them to be swung for one action point instead of two.
In battle, you wait until there's a fair few enemies nearby, and then you use a nearby priest with the frenzy head to apply frenzy to your team, granting even more movement speed. Then, the fun begins.
You use rapid clearance on your whack-a-moler and send them in to melee the nearest human, arthron, triton, siren, worm or mind-fragger. A kill with your high damage melee weapon will refund you two action points, and using the weapon costs only one action point, so you can use the other point to rapidly move to the next enemy. Dashing can only be done twice per turn, so use it when you can't reach your next target without doing so. Each kill gives 1 will point for everybody on your team, and you'll get a ♥♥♥-ton of kills.
I've beaten several missions in one or two turns with one or two whack-a-molers. They're by far the strongest late-game character build. However, don't use them on chirons or Scylla, as those cats just have too much dang HP for this little trick to work. Also, watch out for overwatch, as this can catch you off guard. If you need to refresh your action points, any other assault can give two free points to your whack-a-moler if they are close enough, to keep the killstreak going.