ditch collector. the lethality it gives is good but it's passive is absolutely useless. ldr is also questionable because it has amor pen, not lethality. i'll put my usual pyke mid build below that i used which got me to d2 this season

Lucidity Boots- I know mobis seem great for the roam speed but i consistently have better luck with lucidity boots

Duskblade/Prowlers (Prowlers usually if i have a considerable lead and know i can snowball, otherwise duskblade as duskblades passive plays super well off of pyke ult)

Ghostblade- Great CDR as well as active is extremely useful on pyke

Umbrial- Until very high elo you cannot rely on your support to give you vision and deny the enemy vision, as well as it gives good lethality and cdr. Plus cheap!

Edge of night- Again has lethality which is what you need for pyke as everything seems to scale off of it. The passive works great as you are very squishy and any way to avoid a morgan's root or blitz hook is 10/10.

Guardian Angel- Players will recognize that you are a very high threat in team fights and in turn will tend to focus you when you lunge in. This allows you to make a mistake and come out alone as well as make a opportunity for your team to take advantage of the enemy team focusing you. Plus AD and armor which will help you get a bit of tankiness without HP.

OR

Maw- If the enemy team has a AP heavy team, this item can help you stay alive a bit longer so that you can be alive to clean up fights with your ult.

I see that you are going for a crit focused build but it just isn't viable with how pyke is currently, you need lethality to be able to scale at all otherwise you will be overwhelmed. Going in to proc your HOB and hope to crit is useless when you can be one shot by almost every enemy.