User blog comment:Crimson and Darkness/DxD Updates 2~/@comment-27083298-20170929160908/@comment-30924344-20170929161830

I think Ishibumi is saying it is about 400 pages and that he may have gone to 500. Also this tweet right there seems to suggest he is publishing V24 in 2 parts so 2 separate volumes: https://twitter.com/ishibumi_ddd/status/913795556484329472