Arc Warden seems overly complicated for the sake of being complicated. He just kind of seems like a mismash of various skills from other heroes tweaked a little. A bad version of Oracle's slow, Disruptor's storm for physical damage instead of magical, Terrorblade's enemy ghost thing just a little different and a mix between a Lone Druid bear and Meepo for an ult.
Pit Lord is kind of awkwardly between a newer styled complex hero and an old style kind of low key, more simple hero. He seems a bit better of the two, but at the same time, doesn't seem like he really adds anything major to the game.
all his abilities work well for the purpose of splitpushing or solo pickoffs when you look at it.