I did not have much time doing this guide I played Thresh often at both servers LOLPBE and WEST-EUROPE and so i had much time to see what is good. It can be that you have problems at END GAME and this time but I think i can fix that problem too.Comment if you want ^^. Have Fun !!

Pros

+ very good Chaser with Flay and Death Sentence
+ Escape and Chase with Flay
+ Personal Steroid Seals Rising his armor and ability power
+ Good Early, Mid and Late game damage
+ Good for teamwork
+ have much CC for a ADC

Cons

- Squishy like all ADs
- Highly focused at Late game
- Needs a lot of Seals
- not the best Late game as a ADC

This are normal Ad Runes except for the movement. I did take them in because with them you can chase you enemys much better you must decide if you want early dmg output or a better chasing ability.

Play Video
did not make it so big thx to Pawnce because he does a realy good job to introduce the abilities of thresh

The souls are irreplaceable for your Late game so get them all ^^ when not you will lose. With his souls (passive) he does not to buy armor but at late game he need magic deff because he have no much magic deff at start to Late game. PlS be Careful when you play against an APC or a AP *****.

Combos:
1. Attack: use Death Sentence (2nd time to get behind your enemy) and Flay (when you have phage do Flay later)
2. Chase: when you are near your enemy do Flay hit them twice or so and then use Death Sentence and run away ^^ now use it a second time to get behind your enemy and hit him to end. But when he want to get away use your ult.

P.N.: pls try him with Blitzcrank as the sup it is so funny to have your friend from 5 to 9 sec in your turret range ^^

GOOD Against

Ezreal
Graves
Miss Fortune
Ashe
Vayne
Sivir

BAD Against

Draven
Jayce
Urgot