Originally Posted by begginersluck
Chasing your fish around can cause uneeded stress. Also moving your rocks around all the time wil stress the blenny as they usually have their own 'home'. Moving the rocks moves their home!
I suggest leaving the rocks alone and keeping a close eye on them. Your tang should calm down eventually. Blennies are notorious hiders especially when they feel threatened. Keep in mind they are incredible hiders and your tang has almost no chance of hurting it when he's hiding.
Make sure you are making enough food available to all species. Clip some nori for your tang and give your blenny some mysis shrimp. The nori will help distract your tang.
IME If you have a persistent bully then your tank already has high levels of stress. Not intervening usually leads to loss of the fish under attack.
Using garlic on their food will help boost their immune systems. I've had good luck avoiding ICH using Kent's Garlic Extreme.