Garchomp
General Strategy
Pick your engagements wisely! Garchomp lacks range and chasing ranged characters is dangerous. Try to push forward and grab enemies to move them towards your team, rather than diving into the enemy team.
Your boosted attack is your main source of damage, keep it charged by hitting wild pokemon between fights. If it resets, using your dragon combo properly will get you back to 3 stacks more quickly regular auto attacks.
Try to wait for your opponent's CC moves to go on cooldown before engaging. CC is a showstopper for all-rounders and Garchomp is especially vulnerable due to how it's boosted attacks and move combinations work.
Use the dragon combo (dragon rush + dragon claw) to isolate opponents from their teammates. Garchomp is especially good at pulling away front-lining defenders, which forces their vulnerable attackers to move forward into the range of your team's attackers.
Your unite move is very powerful but should be used wisely. Its best to focus on a singular target because better teams will scatter into different directions to dodge your attacks. Don't overextend with the ult because the self-stun at the end leaves you vulnerable to follow-up attacks.
Don't be afraid to hit objectives! Garchomp is excellent at ripping objectives quickly, once your team gains an advantage during the Rayquaza fight you should make it a priority to shred its health to prevent comebacks. Hitting objectives is also an excellent way to restore your health through Garchomp's generous lifesteal stat.
Support characters are your best friend when playing as Garchomp, try to keep in the range of their healing and shielding abilities!
Items
Scope Lens (MANDATORY)
This item should be present on every build you make, its value is extensive and there are no better items for Garchomp. Boosted auto attacks have two components, a base damage amount tied to your attack stat and a remaining HP amount tied to your opponents HP. Each component can critically hit, which gives you two chances to proc the bonus damage for scope lens. This item also increases your chance of critical hits and the damage that they deal, leading to greatly increased damage during all stages of the game.
Rapid fire scarf (Highly recommended)
This item syncs well with Garchomp's intended playstyle, which is to engage with your dragon combo and then auto attack until your opponent goes down.
Focus band (Recommended for beginners)
Focus band is a commonly used defensive item which can heal a significant portion of health during fights when you need it the most. It is recommended for beginner Garchomp players because it can provide a lifeline during tense fights. Its primary downside is its limit on uses during a game; the item has an 80 second cooldown which means it won't be available for consecutive fights and its method of healing takes 3 seconds to complete, which can lead to "burst through" if under fire from powerful attackers.
Muscle band (Recommended for beginners who do not have rapid fire scarf)
Muscle band is an excellent item for many characters and will always do something for you when you auto attack. Due to the special nature of Garchomp's boosted auto attacks, it quickly loses value during a prolonged fight but it can be helpful when Garchomp does not have its boosted auto attacks. Calculations showed that it can sometimes end a fight one auto attack sooner (dependent on when and how often Garchomp's boosted auto critically hits).
Drain crown (Recommended for very experienced players)
Drain crown is not recommended for any character besides Garchomp because its healing is extremely limited for most attackers and all-rounders. Garchomp's boosted auto performs well with this item because the remaining HP component is eligible for lifesteal bonuses and the bonus HP allows you to last longer during fights. If you are using Muscle band, you should not use this item because muscle band's remaining HP component is not eligible for lifesteal and you will end up healing less than you would without it
Weakness policy (Generally not recommended but usable)
Weakness policy provides a general increase to attack and HP, which is moderately helpful for Garchomp due to its decent attack scaling and frequent attacks. This item generally loses when compared to the items listed above but serves as a substitute when they aren't available.
Path strategy
Top path (not recommended)
Don't go into this path at the start of the game, I highly recommend picking another character when bottom path or central area are not available.
Central area (Best if your team does not have another good jungler)
This area is best left for other characters who need it more and cannot fight well in lane during the early game, but Garchomp can serve as a suitable jungler when needed. It is important to not overextend during your first lane attack because you won't have your Dragon Claw move to slow opponents.
Bottom path (Recommended)
Generally speaking, Garchomp performs best when it has access to as much experience as possible. Aside from the central area (jungle), bottom path has the most easily available experience and its layout is favorable to melee characters. While in this path, your number 1 goal is to reach level 5 before the first Swablu and Altaria spawn at 8:50. If you reach level 5, your Dragon Rush move allows you to move the clouds into a favorable position for your team and start snowballing the lane.