Hello Everyone, my IGN is RoyalArcher22 and I'm the leader of the Rose of Halcyon guild. I figured that it would be a good idea to write a guide about my favorite hero Kestrel, as she can be quite difficult to learn. For some credibility, I currently have five stars with Kestrel and am frequently the top earner on my team when playing her. My single game record for kills with her is in the high 20's. I don't say this to boast though, because it has quite literally taken me years to get to this point with her. She's a very tough hero to master so I figured some insight might help others.
I want to preface this by saying that while the items I'm recommending have proven very effective for me, nothing can compensate for understanding Kestrel's playstyle and mitigating her weaknesses. As such, here are a few tips in general for playing her...
1. Glimmershot is kestrel's best attribute and you should 100% abuse this. With four charges, glimmershot dishes out tons of damage and is THE reason to play Kestrel. That being said, it's a skillshot and requires some practice. Use it to annoy your opponent in the early game and snipe minions in tough matchups. Always go into battle with a full four charges or else you'll be forced to move in for a basic attack and then get run over in two seconds.
2. Stick to the edge in team fights. Kestrel is a ranged hero and as such dies really easily against melee heroes with sustained damage output. When you enter a teamfight, let your tank soak up the hits and stick to the edges while using your glimmershot. You can still be very proactive and impactful just by using skillshots to poke from afar and this build maximizes the damage output of her A.
3. Use her B to evade enemies and lay traps in congested areas. While her A ability gets the most attention, active camo can be just as powerful by stunning an enemy and dealing immense amounts of damage. While you will primarily use your B to evade enemies, you can also set it in the middle of the lane during a teamfight to setup a clutch stun and swing the tides of battle. Furthermore, her B grants a speed boost meaning it can be used to finish off fleeing enemies.
4. Pan the map and use one shot one kill to finish off low enemies. Kestrel has a global ult, meaning it can target anywhere on the map. If you're using a touchscreen, use one finger to pan on the minimap and the other to aim your shot. Keep an eye on your teammates when they get attacked, as a clutch snipe can help them out. Keep in mind though, this ability can be body blocked so don't use it if many heroes are around.
5. Kestrel's glimmershot and ult can snipe objectives. While it is incredibly difficult, good timing and a bit of luck with one shot one kill can steal a dragon away from the enemies. More often, however, I have found that staying behind the brick barrier which houses the dragons and poking with glimmershot can finish off a dragon and turn the tide of a game.
With these tips in mind, I'll move onto her item path!

Start: When the game starts, I generally buy two weapon blades to help last hit and earn more gold. As soon as you recall for the first time buy a pair of sprint boots. Always level up glimmershot first and unlock your B upon reaching level two; however if you have a good matchup in the lane and are a bit ahead upgrade glimmershot again to keep up the sustained damage and frustrate enemies. Active camo is mainly used for evasion and repositioning for a kill this early and it uses up a lot of energy anyways.

First T3 Item: I'm always going for a sorrowblade as my first T3 item as it gives kestrel a solid base of WP to strengthen glimmershot and improve her last hitting ability. After buying the sorrow blade, move on to tier 2 boots and then work on building up to a second offensive item.

Core Items/Mid Game: After getting your sorrowblade, save up for two tyrant's monocles. These are by far the most important items in the build as they allow your glimmershot to become downright oppressive and deal huge amounts of damage. The whole focus of this build is to maximize the strength of her A so that we can stick to the edges of teamfights and take out enemies. I've seen other people go with other builds to strengthen her basic attacks but in my opinion these builds are much weaker because Kestrel is squishy to begin with. Putting her in the middle of fights by building something other than tyrant's monocle means you have to build some sort of defense which detracts from any early advantage you had. Use Kestrel's range and stealth to limit the money spent on defensive items and get ahead.

Late game: After you have the two monocles, things start to get situational. As I said before, the whole purpose of maximizing her A is so that we can rely on her range and stealth and not have to buy defensive items, so these last slots generally come down to tornado trigger, tension bow, or sorrowblade. A good rule of thumb is to take tension bow if the team fights are very grindy so that you stick to the edges, get off a few strong attacks, and reload while the fight continues. Tornado trigger is a viable option for other games where your team may be a bit ahead and you have a good captain that can give you a bit more breathing room to get in and shoot down an opponent quickly. Either way, both items are really strong and at this point you can't really make a terrible choice.

Tips: CP Jungle Kestrel is not very conventional, but it can be very fun as this build takes advantage of active camo so that Kestrel can glide across the map unseen and create some unfair 2v1's for you and your teammates. Just note that with this build kestrel is very weak since she doesn't have a very sustainable damage output and as such active camo becomes very important.

Start: At the beginning of the match, take two crystal bits and level up glimmershot. Take active camo with your level two. Be sure to get the full five stacks of adrenaline when jungling or else you will run into energy problems. Recalling early and often with her is fine, but be sure to avoid early confrontation.

Early game: This is when we start building into shatterglass and moving around the map to try and pick up any easy kills. Be sure to use pings to coordinate attacks with your teammates and set up some unfair situations for the enemy since your active camo allows you to walk in front of enemies undetected. As such, maintaining vision control is really important here.

Core items: After your first shatterglass, look to get a spellfire so that you can apply mortal wounds consistently. After this, you can consider going for more crystal power or instead buying clockwork so that you can constantly be using your ultimate and active camo. Around this point you should be close to perma stealth (Where the cooldown on active camo resets before your become visible) which means you can set up some wild 2v1's.

Late game: At this point, the most important thing is building up more crystal power since active camo will be your primary defensive measure. Look to pick up easy kills and snipe objectives with your ultimate. Furthermore, stick to the edge in teamfights and use active camo in congested areas to set up some stuns that will deal massive damage and turn the tide of a battle.