Hi. I have been experimenting with sirens on knights in dragonspyre (paying them 45 crowns an hour, but they never last that long hehe :P ). A few things I've noticed:
The spell will only remove one blade instead of the two listed on the card (unsure which is in error). Discovered this while fighting Blackback Soldiers, if memory serves.
Enemies defeated by the mighty Sirens will show "damage taken" animation, and show "defeat" animation as they are fading away or they won't get a chance to. Are they supposed to show "damage taken" as water funnel forms, like they do as the lightning sphere forms in Storm Lord's attack? Discovered this in Unicorn Way, when testing Sirens on Lady Blackhope lol. (Some enemies in Dragonspyre seem unaffected, my theory is that they have faster "damage taken" animations. The Fire Scavengers [the sunbirds in the Drake Hatchery] are among the unaffected.)
The accuracy debuff afteraffect is displayed as a -1% debuff, while acting as a -50% debuff (at least I think it functions as a -50%, it made a lot of things fizzle except for Wards and Charms, but I think they just got lucky with those.) Discovered this in Vestrilund, while fighting the grendel from Urt's quest whose name I can't recall lol.