Starting out at level 1 you can walk up to the enemy and Q them usually and stop them from farming, at level 2 is where the magic happens, you taunt them and Q them and if you get them low ignite and go for the kill. At level 6 you have to take full advantage of your R, you are the best roamer for the mid lane and your opponent won't have time to go help their team. If they roam to gank then you can follow them with your R. Also if your jungler needs help in the river do help them, you are strong against basically everyone with your Q and can get easy kills that way. CHEMTANK is AMAZING on shen, if you want to chase people worry not for not having the movement speed to catch them, chemtank does it all for you and even has a passive of making the enemy give up! It's also good for engaging the enemy so your team can start a fight rather than slowly walking up to the enemy and pressing E. This build I believe is way better than AD shen as it also gives your teammates a ton of shield when using R on them and you still do a lot of damage.