This is a little mod that monitor shields on Twin Val'kyr encounter.

NEW: Now it has 2 frames that appears before fight, you can click them to target boss!
P.S. PhoenixStyle has an old version of this. But this addon has higher priority.

/twins or /twinvalkyr - open options
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If you want to announce who damaged shield, who damaged another boss while shield was up or time taken to switch target - you need PhoenixStyle addon to do this.

Example (PhoenixStyle):

[R] Boss healed, on shield remains 124379 HP.
[R] Damage to another boss, no dots and aoe (damage - count): Nick1 (52k - 5), Nick2 (34k - 3), Nick3 (24k - 1),...
[R] Damage in shield and time lost to change target considering debuff: Nick1 (252k - 0s), Nick2 (211k - 0.5s), Nick3 (133k - 0.7s), Nick4 (122k - 1.2s), Nick5 (111k - 5s), Nick6 (5k - -s),...