Optimal 8/9 Stargazers with emblem pattern?

I think Medallion is the pattern that grants the emblem every 5 combats. If you had 3 emblems, what would be the ideal 8 Stargazer build?

Nunu Blitz
Jax Rammus
Xayah Jhin
2 of Lulu/TF/Talon

Would the best 9th champion be Riven+Talon, Corki+TF, or Lulu+Nami?