Thermonuclear smoke devil (Echo)

Thermonuclear smoke devil (Echo)
Released								27 November 2024 (Update)
Members								Yes
Combat level								602
Size								3x3
Examine								Woah.
League region								Kandarin✓
Combat info
Max hit								51 (Magic/Ranged) 99+ (Charge attack)
Aggressive								Yes
Poisonous								No
Attack style								Magic, Ranged
Attack speed								2 ticks (1.2 seconds)
Slayer info
Slayer level								93
Slayer XP								1,200 xp
Category								Bosses, Smoke Devils
Assigned by
Combat stats
1,200				230				220				324				15				387
Aggressive stats
+0				+0				+0				+0				+0				+0
Melee defence
+11								+4								+9
Magic defence
+800												20% weakness
Ranged defence
+90								+90								+90
Immunities
Poison								100% resistance
Venom								100% resistance
Thralls								Not immune
Open in DPS calculator
Advanced data
Monster ID								override499
Link								MOID

Echo Thermonuclear smoke devil is a more challenging variant of the Thermonuclear smoke devil that is accessible during the Demonic Pacts League. To fight it the player must carry a Kandarin echo orb, which is dropped by the regular Thermonuclear smoke devil. Unlike the regular Thermonuclear smoke devil, a smoke devil task is not required to attack the Echo Thermonuclear smoke devil, although a task is required to acquire the Kandarin echo orb from the regular Thermonuclear smoke devil to enter its lair.

The Echo Thermonuclear smoke devil has two unique drops: the Devil's element, an offhand Magic equipment that adds 30% elemental weakness against each element, and shadowflame quadrant, a staff that fires two spell attacks and targets elemental weaknesses.

The fight starts with Thermonuclear smoke devil (Echo) spawning a ring of 12 protective resonance tiles around itself. It will then launch 12 orbs at the player that deal either Ranged or Magic damage in a predictable pattern. After 12 attacks, the boss will use its special attack. The cycle then repeats itself in exactly the same pattern from the start.

Once the boss reaches 50% HP remaining, it enters its Enraged Phase. The only difference is a change in the pattern in which the Ranged and Magic orbs are sent to the player.

Thermonuclear smoke devil (Echo)'s primary attacks consist of slow moving orbs that deal either Ranged damage (red orb) or Magic Damage (light blue orb). The attacks are sent in a pattern of 4 groups of 3 attacks, for a total of 12 orbs. This pattern can be learned for both the pre-enrage and enraged phases. Using R to denote a Ranged attack and M to denote a Magic attack, the patterns are as follows:

Pre-Enrage Phase - [RRR] [MMM] [RRR] [MMM] [Special Attack]

Enrage Phase (Magic) - [MRM] [MRM] [MRM] [MRM] [Special Attack]

Enrage Phase (Ranged) - [RMR] [RMR] [RMR] [RMR] [Special Attack]

The Enrage Phase pattern can be determined by whichever attack it uses first upon entering this phase (for example if the first attack is a Magic orb then the player can expect the Enrage Phase (Magic) pattern to be followed exactly from that point on for the rest of the fight).

The damage from these orbs can be entirely negated by using the correct protection prayer while standing on a protective resonance tile. The prayer needs to be in place at the moment the orb hits the player (rather than the moment the boss launches the orb). Standing on a resonance tile will reduce damage from the boss's attacks by 50%, regardless of the prayer being used at the time. Protection prayers only negate damage if the player is standing on a protective resonance tile.

The resonance tile that the player is standing on will be depleted after an attack lands. The player must then move to another resonance tile before the next attack lands. There is just enough time between each attack in a set of 3 to be able to both move to the next tile and attack the boss with a 2-tick (or 1-tick) weapon. There is more time between the attack sets themselves as well, giving players an opportunity to get in additional attacks or eat if needed.

After all 4 sets of 3 attacks have hit, the boss will perform its special attack.

The Echo Thermonuclear smoke devil begins charging a powerful attack of which the progress is displayed by a charging bar above its health. Once filled, the special attack is launched. The Echo Thermonuclear smoke devil's special attack deals typeless distance-based damage: the closer you are to the boss, the higher the damage. Due to the restricted size of the boss arena, it is not possible to avoid this damage. Standing next to the boss can result in the player being one-shot killed. Standing at the edge of the arena results in 9 damage.

If standing underneath the boss, the special attack's damage is a flat 130.

If standing next to the boss, the special attack's damage starts at 117 and drops by 13 each tile. Two tiles from the wall, the damage is mitigated to 13; one and zero tiles from the wall, the damage is set to 9.

This damage is calculated at the time the attack is launched (rather than when it hits), so players may immediately begin moving back towards the boss even before taking damage from the attack.

After hitting the player with the special attack, the boss will switch its overhead prayer to the same style as the most recent successful attack the player used. This attack must land and generate a hitsplat on the boss; however, it is not necessary to have done any damage with this attack (e.g. a Ranged attack that hits 0 will still result in the boss praying against Ranged). This prayer will last the duration of the next 12 attack cycle.

Upon reaching 50% health, this will begin the enrage phase, where the fight is nearly exactly the same. The only difference will be the attack pattern: either [Range / Mage / Range] or [Mage / Range / Mage]. This pattern will never change for the rest of the fight, meaning all 4 groups of 3 attacks will be in this same order.

Always try to stay on the resonance tiles while the boss is attacking you, whether or not the correct prayer is up. Runelite's Tile Indicators > Current tile > Highlight true tile and Tile Indicators > Destination tile > Highlight destination tile are strongly recommended. The tile the game actually registers your character on and the tile your character is displayed on are often not the same, especially during fast moving combats, and positioning is crucial for this fight. Similarly, make sure auto-retaliate is disabled, especially when using melee or a short-distance ranged weapon. Melee in general will be a particular challenge for this fight, as it requires stepping off the resonance tiles frequently.

If this is your first time attempting the boss, it may be worthwhile to start by focusing entirely on movement and prayer without making any attempt to attack. Move from one resonance tile to another, switching prayers between sets of 3 attacks. The damage can be 100% negated with proper movement, and the special attack will hit a maximum of 9 if you have moved far enough away. You will also have plenty of time to eat food during the special attack to continue practicing this movement for as long as it takes to get comfortable.

With a two tick weapon equipped, you have enough time to move from one tile to another and click the boss to attack. After one of your attacks, repeat this action by moving to the next resonance tile and attacking again. After all three attacks in a set, move to the first resonance tile of the next group of three and either get several attacks in, or else eat food as necessary. Make sure you wait for the first attack in each series to get to you before moving: there is slightly more space between groups of three resonance tiles than there is between each tile in a group, so if you start on the middle tile, the last attack in the series is likely to hit you.

When or shortly before the boss starts charging a special attack, it may be useful to switch to a weak but quick weapon of a different style (like darts if the player is using magic or melee) and throw out one attack before running to the edge of the arena in order to prevent the boss from praying against the style the player is actually using. Forcing a prayer switch is required if the player does not have prayer penetration of their preferred style, and significantly increases damage otherwise.

If Thralls are available, then they can be used as an effective way to set Echo Thermonuclear smoke devil's overhead prayer to the desired style. The thrall will hit Echo Thermonuclear smoke devil while the player runs to the edge of the map to lower the special attack's damage, thus ensuring the thrall's attack type will be prayed against on the next cycle of 12 attacks. The thrall will also double as a nice source of damage, even if the player focuses on their movement and prayers instead of hitting the boss.

During the Enraged Phase, players may find it easier to pray against whichever style has the most attacks for their pattern and just accept some damage from the off-style. Do make sure you're on the resonance tiles still, however: otherwise the off-prayer attack will do approximately 50 points of damage, which makes it very difficult to eat through a whole cycle of attacks, and essentially impossible to do so while still doing any damage to the boss.

For example, if the boss attacks with [Range / Mage / Range], then pray against Range constantly and accept the half magic damage (roughly 20 points) from the middle attack. This allows you to maintain the same DPS so long as you have perfect positioning. The special attack gives plenty of time to heal or sip prayer potions. The boss will hit around 80 points of damage total during each cycle of 12 attacks (assuming no position mistakes) if prayers are not switched, meaning the player will need to heal back up to near-full HP during every special attack phase when doing this strategy.

Alternatively, players can switch prayers between attacks to continue negating all damage.

While the boss has low melee defence, the fight's mechanics are punishing to melee builds. With a 2-tick melee weapon, it is possible to maintain 100% uptime throughout the fight by standing on each resonance tile for one tick and attacking the boss on the next tick.

Vengeance is only triggered by the special attack.

Thermonuclear smoke devil (Echo) rolls the same drops as regular Thermonuclear smoke devil, in addition to a roll for its unique echo item.

	Item	Quantity	Rarity	Price	High Alch
	Devil's element	1	1/25[d 1]	Not sold	30,000
	Shadowflame quadrant	1	1/25[d 1]	Not sold	45,000

This boss has appeared in a previous temporary event:

• Raging Echoes League
  • The unique drop was only the devil's element