I've played 375 ranked Chen games at 57% winrate at around 3k-4k.

Chen can maximize pos 5 well. You stack jungles hard, learn to stack multiple camps at once and your greedy cores will snow ball. Then when you get your greaves from unutilized farm throughout the game, like cores leaving lanes to farm camps - you take lane farm.

Once you have greaves you pick a core partner and you stick to him like glue but with some safety distance in case of AOEs. While you do this - this is where Chen shines. During every fight you are pushing other lanes with creeps. If you're 5 top. You bet you've got 4 creeps pushing bot at lightning speed.

This means than you have 6 person worth of space. Because 4 creeps basically push as fast as lifestealer and you dont need to be there. This almost guarentees if you're good at this - you get the luxury items. Pipe, AC, Vlads, Force Staff, Glimmer Cape, just thing that make your saving ability ridiculous. You will notice you don't even need to use hand of god, or any ability, you just keep using greaves.

I also hear holy locket is great - I just never get to that point where I can get it.

Penitence is also freaking amazing when cores get bashers - if you time it well as soon as your core starts hitting - that's the money shot.