When using this idol, it appears as though it will not trigger if Maelstrom isn’t on my active skill bar. This is not the case with other idols - thorn totem on hit for example works without thorn totem being on the active skill bar. It triggers noticeably more often when maelstrom is on the active skill bar.
When in transformed (werebear or spriggan) maelstrom does seem to trigger even when it was not on the active skill bar. Also, upon exiting a transformed state, there seems to be a small window where maelstrom will still trigger.
When changing an active skill to a different one, it sometimes triggers this idol to activate maelstrom several time in a row.
This idol (even at higher percentages) seems extraordinarily unreliable and inconsistent when compared to most others.