The Legiones are the strongest unit in the Monastery of Ascension, each requiring one of their own respective Ascension keystone needed to kill them once each time. They are hunted for their signets which are in turn used to create the expensive ascension crossbow and its off-hand counterpart.
Level 95 Slayer is required to enter the Legiones' chambers. It is not required for fighting them. This requirement can also be boosted.
The Legiones use fairly inaccurate magic attacks, and are able to summon lightning strikes on the floor that can be avoided, similar to the Corporeal Beast's area-of-effect magic attack. Legios always use two lightning attacks, then a basic magic attack (with the exception of Secundus and Sextus).
These lightning strikes are not to be underestimated; they can deal incredibly high damage based on the player's position, and always hit with 100% accuracy regardless of the player's armour rating. If on the rims of the lightning strike, the player will only be hit for one hit of roughly 1400+ base damage. Standing one step away from the centre will deal roughly 1800-2000 base damage, while standing exactly in the centre will deal 2200-2400 base damage. Apart from the increased damage, the rate of damage also increases the closer the player is to the centre; when standing exactly on top of the lightning strike, damage incurred is twice as fast compared to the edges.
Unlike most monsters, protection prayers/curses will not reduce the damage of the lightning attacks by 50%. It will only shave 200-300 damage from these attacks instead; their auto-attacks are still reduced by 50%.
All Legiones are both poison and reflect immune. They are still affected by leech curses.
The pattern of the lightning can be somewhat controlled: the Legio will use one lightning strike on the player's current spot and the second on the first place the player clicked from their current standing spot. As such, if the player clicks on one spot and then detours to another, the lighting attacks can be completely avoided.
As ascension members, Legiones can only be efficiently harmed with ranged, as they have extremely low affinity against magic and melee attacks.
Power armour is highly recommended when killing the Legiones, as tank armour does not do much against their lightning orb attacks (which have 100% accuracy), even though it may allow the player to survive a potentially fatal hit. If cost and balancing is an issue, pernix armour is highly recommended as it is cheaper than sirenic in the long-term and provides both attack and health boosts.
The Legiones have level 85 defence with 70 affinity towards ranged attacks. A tier 90 weapon will have near 100% accuracy when combined with a super ranging potion or overload. On-task, a tier 90 weapon, tier 95 curse and the slayer helmet will provide players with 100% accuracy, making such potions optional as the Legiones can go down fairly quickly even without using them.
Players can choose between two familiars; beast of burden or combat familiars.
If accuracy is a problem, one can bring a shadow nihil, as when off-task with a nihil and a super ranging potion, a player will have almost 100% accuracy. However in most cases, their defence is usually not high enough to warrant a nihil so players bring the steel titan instead to deal additional damage.
Beast of burden familiars should only be used for inexperienced players to carry emergency food. Typically they are required at Quintus due to his mechanics, though experienced players who are seeking to get the most kills out of their trip can carry additional keystones inside instead. If placing keystones in a beast of burden familiar, players should have a ring of death as the yak will drop all of its carried items in the instance if you die without it.
Luck does not affect the drop rate of the signets, though Hazelmere's signet ring can double drops.
Instead of a farsight sniper necklace and Soul Split, Protect from Magic along with Rigour can be used in combination with an amulet of zealots for faster kills and slower prayer drain overall compared to using Soul Split and ranged turmoil. However, this will require more food if the player is hit too much from their lightning attacks.
Players should engage the Legiones using the hit-and-run tactic - where they attack the Legiones while they keep running around, which will make them avoid the lightning orb attacks most of the time and help conserve food. Each Legio has their own unique special attack which will activate when they reach 75%, 50% and 25% life points. Despite this, the hit-and-run tactic should still be used as normal, except for Legio Quartus and Legio Quintus (see their respective sections below).
Soul Split should be the primary overhead curse; if this is not applicable, then Protect/Deflect Magic should be used as the second priority. Avoid the lightning orb attacks as much as possible for every Legio; Rapid Fire and Unload will hold the player in place until they manually cancel it, which can subject them to prolonged lightning exposure which can result in severe damage or death. Snipe also has the same issue as Rapid Fire and Unload, though wearing Nightmare gauntlets will prevent this from occuring.
When fighting the Legiones, they enjoy a damage reduction the further away a player is from them. Being under them when the attack is calculated will deal full damage, although this is not viable due to their small size. It is recommended to unleash thresholds/ultimates while the player is next or near them in order to maximise damage inflicted. Always watch the Legiones' health, as damage is capped at quarter intervals, so if Legio Primus has 15,532 life points and Shadow Tendrils are used against him, it will only deal up to 533 damage, while the player will take damage to half of what the actual hit will be, wasting adrenaline and food. Bleeds or low damaging abilities should be used near quarter intervals so the more powerful abilities can be used once that interval is breached.
The preferred action bar setup:
With good experience and high-levelled weaponry, one can expect to kill the Legiones in 15-40 seconds.
Each Legio has his own unique ability which intensifies or is performed again when they reach 75%, 50% and 25% life points respectively.
Legio Primus' unique ability is that the lower life points he has, the more damage he will deal - akin to that of Dharok the Wretched. For every 25% life points that Primus loses, his lightning orb attacks gain 200 extra damage (so at 25% life points, being in the centre of his lightning will deal 2900-3000 damage twice per tick for two ticks). Using the hit-and-run tactic as normal nullifies this ability, however it is best to eat up as being caught in the middle of a lightning attack can cause massive damage.
Legio Secundus' unique ability is using the lightning orb attack more frequently as his life points lower. At 75% health, he will use three orb attacks, then one basic magic attack. At 50%, he uses a simple magic attack every four orbs, and at 25% he will exclusively attack with lightning. This is generally not a problem as using the hit-and-run tactic as normal will nullify this ability, however the lightning orbs will be more frequent so having high life points is advantageous when most of his are depleted.
Legio Tertius' unique ability is summoning Monastery of Ascension units when his health lowers - 3 Rorarii when he reaches 75% life points, 1 Gladius when he reaches 50% life points and 1 Capsarius when he reaches 25% life points.
The ascended spawn under Tertius, so they will can be damaged easily with Corruption Shot and Bombardment. The Gladius can be somewhat problematic, but since Legiones take increased damage the closer the player is to them, the Gladius is unlikely to move out from Corruption Shot and Bombardment will only force him to move away from the pile. Should he be able to land a stun, immediately use Freedom and quickly move away before the lightning attack strikes.
The Capsarius can be much more problematic than the Gladius, as it will heal the wounded Ascended, which will almost always be Tertius, though she may focus her attention on the wounded Rorarii or Gladius. As soon as Tertius calls for the Capsarius, immediately use Snap Shot or Shadow Tendrils while adjacent to him. This should either kill him outright or severely wound him where a follow-up ability will quickly dispose of him. If this is not feasible, use Binding Shot or Tight Bindings on the Capsarii and continue the fight as normal; Tertius should be killed before the Capsarius can move out from under him. Prevent the Capsarius from healing him, as her capabilities occasionally glitch and grant her target a permanent damage reduction buff which can greatly slow kill time - if this happens, kill off the minions before focusing on Tertius.
Any remaining minions after Tertius is killed with die off as of the 29 June 2015 update.
Legio Quartus' unique ability is teleporting the player next to him when he reaches 75%, 50% and 25% life points and launching an additional lightning attack at/around the spot he teleported the player, on top of his regular attacks. This act can be seen as both a benefit or threat - if the player is very far from Quartus, being teleported nearby should not have much of an effect to their life points.
Players close by can be potentially hit by the lightning attacks upon being teleported. However, this typically isn't an issue if Quartus has a small breather (roughly 5 seconds) as phasing him almost immediately as soon as he teleports the player will typically result him teleporting them on the spot he first teleported them in, leaving them exposed in the direct center of a lightning attack.
It may take multiple clicks to move away from Quartus as the teleport cancels your action in doing so when using Revolution to fight. Players should also be careful when damaging Quartus when he teleports the player, as he gains a second of invulnerability while performing his special attack.
Legio Quintus' unique ability is summoning "Lines of Ascension" in the laboratory when he reaches 75%, 50% and 25% life points. This is very dangerous and makes Quintus possibly the most tedious to fight for inexperienced players as death is a much higher possibility due to limiting the player's space to avoid orb attacks. The first and third lines he summons will run horizontally, while the second line runs vertically.
Stepping on one of these lines will deal incredibly heavy damage (more than the lighting strike in terms of individual damage) - however, it only hits once if you step across the line. However, unless using Devotion, you'll be forced to move to avoid being electrocuted by the lightning attack.
It is worth noting that the player can "force" the lines to spawn as when he reaches 75%, 50% and 25% life points respectively, a line will spawn wherever the player is currently. Doing this near the edges of the laboratory will effectively nullify them if they perform the hit-and-run tactic while keeping away from them completely - however, players should note that he will take less damage the further you are from him, so this is only recommended for inexperienced players.
Tip: The "Lines of Ascension" are extremely similar to the Queen Black Dragon's fire walls - if you stand next to a line, then run over it, you will not take any damage from the line itself. This can allow for easier maneuverability around him to deal maximum damage without having to bring him closer.
Legio Sextus' unique ability is his lightning attacks - unlike the other Legiones, his attacks are not modified as his health decreases. Sextus' lightning attacks last significantly longer than his fellow Legiones, as they only start to dissipate once three strikes are on the field. In addition to the increased duration of these attacks, their AoE is increased from 4x4 to 5x5.
This should be kept in mind while running around; doing so in an erratic way is not advised as the larger radius and prolonged duration can potentially slow down kills, though his laboratory is fairly large to avoid these attacks while dealing as much damage as possible. Sextus is fairly easy to kill, much like Primus and Secundus.