You want to get Fire Freyr over Vahagn imo.
Vahagn is nice and really strong but tbh you will hit the 2mio cap way easier with fire Freyr.
And she also has 30% fire rst down. She is the fastest fire KH up to date and she can hit like a truck too.
Furthermore Uriel will be out of the meta, mostly for fire bakas who can reach the 2mio cap.
If you think you wont hit the cap next year, then please just get Uriel.
Otherwise Fire Mammon is the imo the 2nd best choice to MT for fire.