>>528326653
If you tap E her burst gets replaced by a self-buff that absorbs all the rifts that your team made(you want to use this burst when the 3 indicators on her meter light up, and then do a CA the second time they light up), and your meter is completely gone when your infusion ends
If you Hold E you gain 45 meter and absorb the rifts(they grant meter), you need 50 meter to use her normal burst so you need to absorb one rift(ideally 3 to maximize your burst damage)
So you when you press/hold E you choose if you want to use normal attacks/your burst.
The only exception is when you have your bust icon filled before the fight starts (this can happen when you start the abyss/when exploring around if you held E to move faster, since holding E doesn't consume your meter, just gives you 45), then in these cases you can use your supports then Skirk's Q for a normal damaging burst and then tap E into her normal attacks.
Basically she has two modes, the normal DPS playstyle and the nuke burst DPS playstyle and she can swap between them depending on what you need at the moment.