best eras for a targaryen si/oc fic?

i’m planning on writing a targaryen si/oc fic but i can’t decide which era i should do

my top ones are either maegors reign, jaehaerys reign or during one of the blackfyre rebellions but i’m open to any other suggestions

to give a summary si/oc is sent by the fourteen flames to prevent the downfall of house targaryen (pretty basic plot) i have different ideas on how i want to do it but one of the main things is si/oc knows very little about the era they were sent to