(I'm not the one who noticed this interaction, credit to Ol Bill on the TOS Discord, just wanting to bring it to Wyrd's attention for future FAQ)
Knocking Down the Pillars of Reality: On any Turn after the first, if there are three unengaged Fireteams in this unit, discard the top card of your deck for every enemy Fireteam within the triangular area between this unit's Fireteams. [...]
If someone hires the ECB Black Ops with the Icon of the First World, then what is normally a three Fireteam unit suddenly has a fourth Fireteam. RAW, I think this means a few things:
The ECB Fireteams can still use Knocking Down the Pillars of Reality but only if exactly one of their four Fireteams are killed or engaged
If one of the ECB Fireteams are engaged and the others are all alive, the engaged Fireteam can use Knocking Down the Pillars of Reality because it doesn't say anything about the user having to be unengaged
The "triangular area" is a bit of a problem too, RAI it seems obvious it means "between this unit's unengaged Fireteams" but if the way you're getting exactly 3 unengaged Fireteams is that the 4th Fireteam is engaged you technically have a four-sided shape you could be drawing an area from because RAW it just says it's the area "between this unit's Fireteams."