Gai stated that his 6th gate Morning Peacock was nothing compared his 7th gate Daytime Tiger.
Yet, Gai can take on Tailed Beasts with Morning Peacock.
Morning Peacock is nothing compared to Daytime Tiger since the Morning Peacock could barely hold it's own against a fake 30% Kisime while the Daytime Tiger easily took out real Kisime(who's Bijuu level) and obilerated Madara's Susano'o
If just one gate above makes the previous gate look like nothing, then the 8th gate makes the Daytime Tiger look like a complete joke. But this complete joke was able to challenge the likes of regular Madara.
By powerscaling, the final gate can destroy Hashirama or Regular Madara.