The Fusion , also known as the Karash Knot is a knot proposed by the FFS as an alternative for the Bowline on the Bight in situations where clipping a single loop may occur.
The Fusion Knot is a double loop knot that can be used for attaching a rope to 1 or 2 anchor points as is common in SRT. The name comes from the fact that the knot is formed in the same way as a Bowline on the Bight but uses a Figure of 8 Knot as its base as opposed to an Overhand Knot, a kind of fusion between two knots.
Once formed the body of the knot contains an additional structural turn to the 2 rope strands that enter from the working ends. The nature of this knot should give the Fusion good holding power but less shock absorbency than a BotB.
You’ll need a Figure of 8 Loop to start with, with practice you can measure the arms for your Y-hang before tying, just like a BotB
Now push the loop back towards the body of the knot. This will cause 2 strands to be pushed out of the back of the knot body. Once you have these 2 strands, continue to pull them out of the knot body forcing the loop to slide up the 2 working ends and jam against the knot body.
The 2 strands you pulled out now form your 2 loops for the anchors
Dress the knot, tighten down and make any adjustments to loop length you need.
Here we have the Fusion aka Karash Knot.
If you are looking for a knot to replace the Bowline-on-the-Bight in rigging for SRT then give the Double-Bowline-on-the-Bight a look also.