This guide is dedicated to showcasing the various different paths that fire can take when flaming. These paths will differ depending on where you click on the screen.
General introduction to Fire paths:
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NOTICE: THE Xs INDICATE WHERE YOU MUST CLICK
COORDINATES COUNT THE TILE YOU'RE ON. (2, 6) MEANS YOU MUST CLICK 1 TILE RIGHT OF YOU, AND 6 TILES NORTH.
Red Targets = Enemies
Grey Targets = Allies
The right image depicts a likely scenario in which the fire path will be useful, while the left indicates where you must click to attain the pathing.
2 Tile Flame Pathing:
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3 Tile Flame Pathing:
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4 Tile Flame Pathing:
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5 Tile Flame Pathing:
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Firing while Moving:
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Extinguishing Yourself:
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Useful Tips:
Tip One: Flame Resisting
Xenos who resist when on fire are inflicted with a nasty 4-5~ second stun. This is arguably one of the strongest features of fire, and part of the reason why it's so deadly to xenos who are alone. This means that you'll have more than enough time to catch up and finish off the xeno while they're resisting.
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Tip Two: Light
Fire emits light. Burning xenos and people also produce light. This means in a dark environment, you can comfortably chase a xeno who's off your screen just by following where the lights are going. Although this requires higher game sense, you can also use this method to bait a xeno into resisting by never entering their screen until the light stops moving - which lets you know that they're either resisting or standing still. They'll be lured into a false sense of security since they'll assume you didn't chase, leading to them resisting early.
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Tip Three: Refueling
The Pyrotechnician Backpack can be used to refuel - but it is bad practice to actually carry it on you. It takes up a valuable back slot which can be used for a satchel that'll hold more tanks and extinguishers, or a secondary weapon such as an M37, L42, MOU, and more. You will not run out of THREE fuel tanks fast enough to require an immediate refuel. It is much better to leave the backpack at the frontline FoB.
Tip Four: Napalm vs Gel
Gel Fuel (the green one) does much less damage than Napalm, and disappears much faster. But, it has a much larger firing range (7-8 tiles compared to 5). For these reasons it's likely to assume that Gel Fuel is perfect for frontlining, but this is in fact the opposite. Napalm does much more damage, and burns much longer allowing you to catch other xenos attempting to flee. It can also simply be extinguished whenever you need to push. Even a single fire tile left standing could lead to a xeno's death if they run through it. Learning to extinguish your fire after you flame is also good practice to learn how to operate with other people at the front.
Gel Fuel is situational, and is best used for clearing resin holes, swathes of hive weeds, sticky resin, and hitting ranged xenos just out of your range.
Tip Five: Eject Magazine
Macro the command Eject-Magazine to quickly unload the current tank at the press of a button. This is very useful for swapping on the fly when your tank is running low, as it cuts down on an additional click, and you don't need to wait for the tank to hit 0 to auto eject.
Tip Six: Anti-Heal
Xenos on fire can not be healed by Wardens, Drones, or Queen Healed. Be sure to always chase a xeno who's on fire just incase they decide to resist early!
Video References
I have several videos up depicting the aggressive use of the flamethrower, as it has one of the biggest, if not THE biggest, push potentials in the game.
SHORT VIDEOS
https://streamable.com/iv0kof
https://streamable.com/ybe90u
https://streamable.com/lrmf9j
LONG VIDEOS
https://youtu.be/xP5Mu9A4O88
https://youtu.be/qjH3MhXVFuo
https://youtu.be/-gWnWWSiy04