Like the topic says...this is a Seinen. The magazine it's published in had a short stint as a Shounen magazine; however, it's been a Seinen since then(and was founded as a Seinen magazine). The slogan is "High Quality & High End Seinen Comic Magazine!" (ハイクオリティ＆ハイエンド青年コミック誌！, Hai kuoriti to hai endo seinen comikku-shi!)" for heaven's sake! :/

It had a 7 year stint, which isn't as short as you make it out to be. Cross H apparently was initially published in 2014, while the magazine was still in its shounen phase, so I'm leaving it as is.

A just ruler amongst tyrants