To start with, no one took credit for that Jinx on Niall, so it won't factor into this roll, but you guys have more dice.
Polly's Flirtation:
Mental [roll0]+ Influence [roll1] + Tricky Pixie [roll2] + I'm pretty,and nice, and smell good [roll3] + Morgan VoC [roll4] + Niall's Infatuated [roll5] = 25 (with 2 Plot Points)
Niall's Insight:
Mental [roll6]+ Influence [roll7] + Rising to the Top [roll8] + Polly's Genuinely Flattered[roll9] = 24 (with a Plot Point)
MOAR JINXES!!! You're Jinx gives you an extra Plot Point, and I think I'm going to use it to step up that Genuinely Flattered to a D12.
Alright, continuing his pattern of rolling well against you, Niall wins the roll, so you burn a Plot Point to swing ahead, which he'll counter with a Plot Point of his own (because I feel like heating things up a bit), so you have to spend your last Plot Point to beat the tie, since ties go to the defender.
This brings the new Plot Point Totals to:
GM: 2
Milesdfp: 3
Orick411: 0
Lynnosa: 0
Don't worry, you can always replenish those in later conflicts by picking a Distinction that opposes the action and rolling it as a D4. You guys did basically start with the boss fight. Mooks will be easier, I swear (unless someone goes crazy).
In any case, the mark has been made. Yuan is now free to show up and start trouble because Niall will implicitly trust you as long as you are playing to what you have made him believe about you. You can also feel free to write his filler dialogue if you like. You're out of the conflict, so I don't need 100% control of him anymore.