This is a plan in several parts, and requires taking F!Aegon alive.
First, we get the amulet we took from Varys upgraded by every deity we're friendly with. This is Yss, the OG, the Merling King, possibly others if we can convince them to. If the Moonsingers are about freedom (I think they are?) we might be able to get them in on this too. We turn the amulet into a minor artefact, but in doing so, we modify it from a defence into a snare. The point of this is to turn it into a focus that all of our divine allies can connect to and use when the time comes.
In general terms, the amulet is designed to be a giant well for divine power. When we try to break F!Aegon free, Timmie will try to stop us. In doing so, she'll Act upon the mortal realm. The amulet, when around the neck of someone who is being Acted Upon by a deity, is designed to siphon off all of that power into itself. Due to how I'm pretty sure gods work, this means Timmie will have suddenly poured a considerable amount of power into what's basically a honey trap. She's also now metaphysically connected to the coordinates of the amulet, and where it currently is. This is important.
We do this at the location of the ruins for the Red Orb, built up into a full Snare around defences that we'll probably have to spend a long time researching in hopes of reactivating and bringing under our control. This is a research action all on its own. When Timmie hits F!Aegon in the hopes of hitting us too, we lock the part of her that reaches out in place with the amulet. Our Gods act as the hooks for this trap, latching on and
keeping her there, a piece of her essence stretched out as far as we can. We then 'aim' the Worm at the thinnest point of that connection and...well...let it fly.
If all goes to plan, we shatter the link Tiamat has to F!Aegon, and also rip off a whole
bunch of her power and trap it in the blessed Amulet. What we do with that power, be it use it as a way to give Mythic Power to more of our Companions or just feed it to one of our Gods to give them a new domain, is a matter for then.
In simpler terms, there are at least two Research Actions here.
- The Amulet that Varys wore is a potent defence, but with what you know the the Golden Company and Tiamat's investment in the false Blackfyre, it might be turned to use as a snare. Seek a way to modify the device in this way, and set the blessings of your divine allies upon it as hooks to catch the power of any god trapped by its presence.
- The fortress-ruin that held the Orb of Dragonkind still holds leashed power unlike anything you've ever sensed, but it remains dormant for now. With time, it might be possible to reconstruct the controls of that power, and with proper preparation use it as a weapon to slice away part of a god.