I would suggest adding in animation module, blade of the blood chief, citadel siege, walking ballista, endless one, hangar back walker, hythonia the cruel, kalitas traitor of ghet, karpov of the ghost council, krav the unredeemed, maga traitor to mortals, marrionette master, and mikaeus the lunarch. If you still need more help, I would suggest going to one of these two websites and searching what you need.

EDHREC: https://edhrec.com

Gatherer: http://gatherer.wizards.com/Pages/Default.aspx

I think your deck needs more ramp to get out that huge commander--things like Thran Dynamo , Gilded Lotus , Black Market and the like can really help to get that 7 mana a lot faster.

To make room for them, I think you can afford to cut Ayli, Eternal Pilgrim , Viscera Seer , and Yahenni, Undying Partisan --Your commander is already a sac outlet, so I don't know how many more you need.

Animation Module - Missed out on that one, great idea

Blade of the Bloodchief - I feel as though it's not gonna be used to its full potential most of the time, since, while Vish Kal likes counters, this deck isn't a counter deck that much.

Citadel Siege - Same reasoning

Walking Ballista - Maybe, but I have reservations about adding it since I can't really see myself ever using the ability to gain more counters, so it'd enter with x counters and id either sac it to Vish, or use it all up to blast someone.

Kalitas, Traitor of Ghet - Already in.

Endless One - Similar reasoning to Ballista

Hangarback Walker - Definitely can see it being useful, though I worry I'll never really cast it for a high enough x to get that much out of it

Hythonia the Cruel - Too expensive really, trying to keep the cmc as low as possible

Karlov of the Ghost Council - Lifegain is just a byproduct of the cards in the deck, I might actually make it less lifegain oriented, so while he can be great removal, I don't think he'd be that useful. Might take a bit more consideration to full decide

Krav, the Unredeemed - Not really sure about him, maybe board for now

Maga, Traitor to Mortals - Would be way to expensive to cast to get a significant amount of life drained, can only see him being played late game to get that final bit of damage in.

Marionette Master - While a great card, I don't have any ways to sacrifice artifacts, so her ability is moot

Mikaeus, the Lunarch - Not a counter deck

Thanks for your suggestions. I think I should refine the objective of the deck a bit more and appreciate your assistance, WarriorMagic

MagmaArmor0, I was also feeling as though I could use a bit more ramp, black market was definitely a miss, but I don't think I'll be running Lotus or Dynamo for the fact they're pretty expensive in cmc, and I'd like to refine the deck so that it could be competitive (though granted Vish Kal isn't really the best commander for a "competitive" edh deck)

I'll gladly remove Yahenni, as I've had doubts of his worth ever since I put him in. As for Ayli and Viscera, serious consideration would have to be made. Viscera is a free sac outlet, she has been really useful thus far in exploiting death triggers thus far, as for Ayli, she's removal for the most part, and unless I get another source of removal, I don't think I'll be replacing her.

And you can never have enough sac outlets! XD

Thank you for your suggestion, I appreciate it!