When Solomon releases is Merlin the first banner?

Less than 24 hours is probably the time, people be crazy

Yes, I believe he is. I'd rather farm pillars first, the Merlin banner will last a week or so. I'm not entirely sure how fast they fall.

It will be less than 24 hours, considering FGO NA is Global, guide/walkthrough is easy to get plus there are lots of Raid videos, especially Solomon.

Don't expect it to live long !

Someone said to me in a different question that the Barbatos pillar fell in 3 hours or something crazy in Japan. I don't know the difference in active players we have compared to what Japan had at this point in their server however.