Baccano!
Prohibition-era immortals across three timelines, opened by a sequence that introduces about twenty characters in ninety seconds.
1 sequence
Season 1
No usable clip verified. The 4K result gives no source and could not be confirmed as the broadcast opening; searching the Japanese for an opening establishes why, in that every copy including that one is creditless and carries no text in any sampled frame.
No footage of this sequence has been found yet.