Gyre identifies the target, the source of tNet, the infinite light to which W connects, and knows what must be done. A perfect strike is required to reach Her but to make the attempt Gyre has to pass through W and that's when things get weird.
Marie and W flirted for months without meeting. Once they locked eyes, their paths began to intersect, they became increasingly attracted to each other, not because of hot looks, or dressing well, or making one another laugh; their unnaturally strong attraction came from something inside - Gyre inhabited Marie.
W and Gyre are twins, counter rotating twin vortices that naturally attract, fluid flow pulls them together. Once these types of vortices get in close physical proximity, collision and annihilation are inevitable and that's exactly what happens to Gyre and W.
Gyre, ready to take down the tNet source, leaps toward Her, the trajectory goes right through W, and the dynamics of their collision consume them both.