Hey^^ its just my recommend. xD I have very much situations where i have to chase and a big minion wave is before my Thresh. You can buy this item if you want, or an other item. I will edit it ^^

The build isn't -too- horrible but the guide itself is really empty and lacks so much content. If you check out some better rated guides you can see what effort people put into explaining their choices. Faerie charm start, second Philo, Mikael's, Eleisa's, Ionians an Phantom Dancer should all be left out of the build. Mikael's is kind of situational in a way, though, so you could leave that somewhere in the build. And also exhaust isn't the optimal spell for Thresh, Ignite is - which you don't even mention.

you also should ask for permission to use someone's fan art in your guide.

Getting Phantom dancer just to avoid unit collision is completely and utterly pointless.
Especially on a support.