Flashpoints SWTOR

Flashpoint Guide: The Battle for Ilum (Normal & Hardmode)

Updated for 1.1 to reflect the change in Krel Thak’s diffculty

This guide is co-owned and first released on


Hey everyone, today I will cover the flashpoint The Battle for Ilum. This is one of three level 50 flashpoints. It is a medium sized flashpoint, taking on average about 30 minutes to complete.

Gark the Indomitable

This is the first boss you will encounter. He has 102k HP. This boss has some basic abilities that can be interrupted but most important part of the fight is the adds that spawn

  • Hail of Bolts – Conal channeled attack, can be interrupted. Make sure the boss is turned away from the rest of the group.
  • Concussive Round – knocks the target down if not interrupted.

Three adds will spawn periodically, they are called Allied Gamorrean Grunt and will gang up on the healer if not picked up. These adds only have 5k HP and can be killed quickly.


Overall very easy and short fight.

Hardmode: Tank need to pick these adds up or they will chew up the healer in no time. Easy fight otherwise.

Video: Hardmode version


Velasu Graege & Drinda-Zel

These two come together, Velasu is ranged while Drinda is a melee. Velasu should be taunted by the tank but Drinda likes to randomly leap to a party member and smack them. Drinda doesn’t hit hard and can be easily handled by whoever it is attacking.  There are also 4 turrets that will shoot things at your party. These turrets spawn when Velasu gets below 50%. There is no point in killing the turrets as they will just respawn.

Velasu have the following abilities

Drinda likes to do Force lighting which can stun whoever he is attacking.

We killed Drinda first, Velasu next and then the 4 turrets.

Hardmode: Those turrets hurt but don’t focus on them. Just burn down Drinda first and then the Velasu. Don’t waste your DPS on the turrets as they will just respawn and may cause you to fail on the very stringent enrage timer (about 2 minutes). You can CC the turrets if need to help out your healer.

Video: hardmode version


Krel Thak

As of patch 1.1, Krel Thak’s adds were reduced in diffculty, making this fight a bit easier. The main thing I want to emphasize is that melee cannot attack him when he has proximity probe up or you will possibly kill yourself for no good reasons (and make your healer hate you). The probe is hard to spot but if you see him with the defensive shield up, there is a good chance the probe is up as well.

**Note: You can skip Krel thak if he is proving too much trouble. Have the tank put up defensive cooldowns and run past Krel and his adds while rest of the group exit area. Tank keep running until you see the quest objectives update. Non-assassins tanks will probably die and get rezzed when the group zones back in at the new zone in point.

This is the most challenging boss in the flashpoint. He comes with two adds initially (if you pull him out, the two initial adds do not come) and has the following abilities

  • Stun: 3-4 second stun on all party members, he does this right before he summon 4 adds. This is indicated visually by the appearance of the holographic icons.


  • Adds: 4 adds pop that don’t have a lot of HP but they hit hard (800 to 1.3 k damage per hit) so if they are not picked up they will gang up on the healer. These spawn right behind where Krel stands.
  • Random target: This will put a lot of stress on healers as Krel loves to randomly target a group member and fire his abilities at them. This makes a challenging fight for the healer to keep everyone alive (can have that person being targeting try to LOS the attack but this isn’t really necessary in normal mode)
  • Defense screen & Proximity probe: He casts Defense Screen Projector every other wave of adds, starting with the first wave. This pretty much make him immune to damage for a short duration but can be interrupted (1.5 s cast). If any melee tries to damage him at this time, they will be counter with proximity probe which will knock them back and pretty much one shot them (one shots the tank with 7 K HP left). So when you see this shield up, don’t melee him and get away from him!



So pretty much for this fight, kill the adds when they pop, interrupt the defensive shield casting if you can or otherwise don’t damage him when the shield is up (especially melee tanks/DPS). It can get a bit rough.

Hardmode: This fight is very challenging on hardmode and it is basically a DPS check and also a tank/healer check. We had him down to 15% multiple times and each time failed because he enraged and one shot the tank. You can pull the boss away from his area to give you sometime to kill the adds. You also need to interrupt his defensive shield and get away from him when he has his proximity probe up. You basically need to chain interrupt him because when you first interrupt him casting that defensive shield, he will cast proximity probe and then go back to cast that defensive shield.

The reason you need to interrupt that defensive shield is that he has a very short enrage timer. If you spend too much time killing adds and not on him he will enrage and one shot the group. You cannot damage him with the defensive shield up. One DPS should be focused on killing the adds and the other DPS+ tank focus on interrupting the defensive shield and focus all their DPS on the boss.

If you cannot beat this encounter, get better gear and try again. It is one of the most challenging fights in hardmode. Also having two ranged dps or powertech tank will help out as this fight is not exactly melee friendly.

We were able to defeat this encounter in hardmode by using two ranged DPS good with AOE abilities (mercenary and sniper). They can alternate their Orbital Strike/Death from Above to handle the adds easily. They also have the advantage of not standing near the boss and getting damaged from the proximity probe. The combination of the two made this fight very trivial (we one shot this after wiping about 10 times with a melee DPS).

Video: (hardmode)



Commander Folek

Very easy mini-boss before the last boss of the instance. He comes with a whole bunch of adds including an elite Forsaken Sith Marauder that can be CC’ed. The rest of the adds are either Weak or Strong type of mobs. One of them was a healer so we killed him first.


Darth Serevin

This is the last boss of the flashpoint. He comes with one add that should be killed ASAP.

First phase of the fight is largely tank and spank except periodically he likes to grab a crystal shard and throw it at a party member, hitting them for 3-4 k damage. He also does something called Dark Blast on the tank (it’s a purple circle thingie). As a sith sorc, it is nice to shield everyone in the party with your static barrier, absorbing some of the damage from the crystal shard.



After this phase, he goes to phase 2 where he goes invisible and pop up right beside a random party member and grab them into the the air and stun them with lighting. At the same time he likes to grab another crystal shard and smack someone else with it


Aggro seems to reset from this so tank may need to taunt him again. He will do the invisible thingie twice and then go back to phase 1.

The rest of the fight is pretty much a repeat of alternating phase 1 and 2.

Video: Normal Mode


Hardmode: Pretty much same thing except the damage is increased. Shield from sith sorc/jedi sage definitely can help out mitigate some of the damage. Dropping an AOE heal once in a while can also help your group recover. There is quite a bit of AOE damage in the beginning as the DPS should be focused on the add and will probably steal aggro from the tank.

Video: Hardmode


By Dulfy

MMO guide writer and blogger. Currently playing and covering SWTOR, GW2, and TSW.

7 replies on “Flashpoint Guide: The Battle for Ilum (Normal & Hardmode)”

You fail to mention that the last boss has an ability called Force Explosion which MUST be interrupted or else the entire group gets hit for a lot of damage. It’s not as bad as Malgus’ Unlimited Power (Everybody seems to survive rather than just the tank), but none the less, if left uninterrupted it can cause a lot of stress for the healer of the group.

Interesting, thanks for pointing that out. Never really noticed that personally, just thought all the damage was from him throwing out the crystals. 

Yeah, as far as I could tell, all his channels were interruptible on Hard mode, so it pays to try cutting down on the damage he does.  Good guide, though, thanks!

There is also a boss you can unlock from doing the bonus quests. The bonus quest starts with damaging enemy turrets and finishes with getting crates of mining supplies. The boss that follows is in the back of a cave after Krel Thak before you cross the bridge.
I can’t remember his name but it’s a huge beast. I was tanking and I remember he has an ability he does frequently that stuns everyone for a moment and then throws you all back. I lost agro each time he did this. Overall though no harder than other bosses in here and he dropped a nice upgrade for someone in our group. Most groups skip the bonus and never see that boss.

[…] he's going to use The Blade will not wound, icon of a shield with a green blob on it. This will . Flashpoint Guide: The Battle for Ilum (Normal & Hardmode) – Dulfy This pretty much make him immune to damage for a short duration but can be interrupted (1.5 s […]

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