All the core bows have really good synergy with Ashe's kit as well as with each other.

- Galeforce will give you insane movement speed and chase/kite potential, which synergizes really well with Ashe's kit. It also gives you a dash, which is really nice on a champion with low mobility like Ashe.

- Runaan's Hurricane has always been core to Ashe, not much to say here. It also builds off Zeal, so it gives even more movement speed, on top of the Mythic passive.

- Mortal Reminder is a pretty cheap and really good all-rounder item (crit, damage, attack speed), and also builds off Zeal, which gives you even more movement speed. It's still gold efficiente even without the grievous wounds passive. Good option for second item if you're behind and can't afford Runaan's Hurricane.

- Last Whisper as a fourth item is a really good option on any ADC really, by this point in the game most bruisers and tanks will have build a hefty amount of armor.

This is actually not a troll build, even if it is a meme build.

Strong movement speed, strong damage, insane kite potential.

The movement speed buffs from Galeforce's passive and Zeal items, on top of Ashe's slow passive will allow you to kite and chase pretty much anyone.

Even if you are focused by an assassin or you're caught up in a really bad position, use galeforce+flash+W and you can escape from pretty much anyone. You can mix a basic attack in between if you have enough time to apply the Fleet Footwork movement speed steroid on top.

If someone tries to escape, use W+Galeforce. Chances are if they're still alive, you will be in range for an auto and will proc fleet footwork to chase them down.