Just a question, why a crucible in the build? Is it just for health or does it actually have a purpose.

Hi! Thank you for your comprehensive reply! Mostly I agree with your points. This guide was made by me as my initial thoughts on playing Phinn as I noticed that there was not any guides on him yet. That is why this guide is so brief and I come from the assumption that it is not for newbies. Of course, when I talk about combos I do not say that you should do it by yourself. If you play support, you just cant be by yourself. These combos is for initiating a teamfight when your teammates are nearby and ready for actions. I even recommend you to ping your teammates "I'm going there" on a hero that you want to grab with your hook. In that case they will be ready to attack him.
As I said this guide was brief and wasn't intended to be comprehensive analysis on Phinn. But I think I will update it in upcoming days to make it more descriptive.
Also, I agree with you, that it's better to take 2nd ability as you'll get your second point. Now I can even say that you should upgrade it as your first, cause it's crucial for early game team fights. But still after that you have to rush for Overdrive of 1st ability.
But I do not agree with buying Contraption instead of Warhorn. I just always leave space to have scout traps and flashes. Scout traps should be placed wisely in early and mid-game to get you vision for most of the time and in late game you just use flashes. If you will use them effectively this strategy would not cost you any substantial sum of money.

First off, great guide you have there. I love the way you talking about jungling and Phinn's build paths. The advice you gave about the abilities was also well thought-out and I mostly agree with that entire paragraph. However, I would like to advice you to acquire the second ability at Level 2, as pulling in the enemy, if they overextend or are trying to gank your laner/jungler, is essential as a tank, as you want the enemy to target you and not the laner or jungler. Secondly, initiating with your ultimate is extremely hard, unless you have good communication with your teammates. Assuming you pull them in successfully, your teammates and the enemy team might be just as surprised. Your team would not be prepared to react or might have walked away, which only brings more danger to yourself, while wasting your energy and Ultimate. The Ultimate shines during team fights where the enemy team is running away. A well-placed Forced Accord might bring the entire enemy team right back to your team. If the enemy team is spread out and bringing back the entire enemy team is not possible, aim for the Ringo, Vox, Celeste, Taka or Krul to use your Ultimate on. They are squishy and can be killed easily when on low health, or full-health for that matter. Just beware of Krul and only bring him back with your Ultimate when he is lower than half-health. Secondly, I would like to request that you add in a new Chapter about going up to lane to support the laner in 2v1 situations or ganks. Overall, I enjoyed reading this guide as it covered the most important points about Phinn, but sections about positioning, supporting and early to late-game gameplay could be added in. Lastly, I would suggest that you use Contraption instead of Warhorn as map control and vision is more important than being able to sprint for 3 seconds. You might argue that you don't need map control and vision if you can simple use Warhorn if you get ganked, but ganking would not even happen if you have a Contraption and use it well.
Thank you for reading :D

I still feel that joule is more tanky than phinn by building more health and armor items or is it just me.

This has been the most useful for me alwhen using phinn, afterburner boosts the abilities and I'm able to stun groups of enemies(minions&enemy heroes) at one time. Building the defense first and getting those boots is crucial in the beginning of the build. Good job with this build!!