This fight can feel a bit awkward as a Mistweaver with the differing time portions and requirement to burst heal the Time Release mechanic. Depending on how high your raid stacks Power Overwhelming, you can get some good use out of Essence Font and Mana Tea during this time, as well as Chi Burst as the raid should be stacked while Power Overwhelming is going on.
If you take Diffuse Magic, you can use it to mitigate the damage either from Power Overwhelming or from getting caught in a bad series of Temporal Orbs. Healing Elixirs are also useful and Roll or Chi Torpedo are handy for getting away from the raid with your Time Bomb.
If you get the fast Time Release mechanic on yourself, you can manually pop both of your Healing Elixirs for some on-demand burst healing. You can use Transcendence to maneuver around the boss room, particularly when running back from Time Bomb.
In Mythic difficulty, the most difficult mechanic to handle as a Mistweaver is the fast Time Release mechanic. Ideally, you will have a charge of Thunder Focus Tea available and can use an instant Enveloping Mist. It’s also sometimes useful to let your Sheilun’s Gift stack higher than you might otherwise to get some burst healing when needed. Otherwise, Vivify under Uplifting Trance can be used to good effect.