Casting Thunder Focus Tea grants 2 charges of Potential Energy. Your next cast of Tiger Palm or Vivify consumes all charges of Potential Energy to cause a Harmonic Surge.
Harmonic Surge:
For each charge of Potential Energy, deal 836 Nature damage to your target and 836 Nature damage to other nearby enemies, and heal up to 5 allies for 190. Damage reduced above 5 targets.