New-ish player mordekaiser question

Hi, sorry if this is the wrong spot, it's my first post.

So I started playing this game on patch 5.16 and purchased mordekaiser on a friends recommendation. He's crazy fun to lane with bottom because with minions around he doesn't care about poke due to shield.

Anyway, I am disappointed I never got to play old mordekaiser. What made riot decide to alter him so much? Remember I never played before patch 5.16 besides a lil bit back in season 3 sorry I don't know the meta before now.