Honestly, this is hard to say.
We have Sera who doesn't want to give out any information about his role when asked. (Sus).
We have Rej claming Fleur and BD himself with Sera. Knowing Sera's position, It wasnt the best idea to BD yourself with Sera. I mean. Also like someone already mentioned, Rej is an very experienced player and it bothers me that this is his 'claim' if he was scum. The moment we lynch Rej and he turns out to be scum, we can also look in Gramma again, who said a lot of times he puts Rej in his town read. Gramma targeting Destroya, who got killed and janitored? Really?.
If we decide to Lynch Sera, and Sera turns out to be town, there is is a high chance Rej is scum. So enough info to gain with both lynches,
I think lynch either of them is fine to me, leaning more Sera because of D1, but if you guys decide to go for Rej, I wouldn't mind either.