Phase 1: Stay in melee range, don't use pets, and dps her down to 30%. If you get Wrack, you will die.
Phase 2: get into bubble for transition and kill the whelps. Dps Sinestra until the shields on the eggs go down. You need to get her mana down to around 50%, if you are having trouble with this your dps may be too low. Once the shields are down kill both eggs asap.
Phase 3: Dps down Sinestra as fast as possible and use any defensive abilities if you need to.
Congrats on killing Sinestra, you are now a Dragonslayer!
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