Jarad, the selfless - Just a small sacrifice for the greater good... (EDH / Commander)

Main strategy:

Jarad’s main win option is winnig by life loss due to his activated ability. Therefor it is helpful to have big creatures for little mana like Lord of Extinction, Mortivore and Nighthowler, creatures which can get big like Ravenous Slime or Wall of Blood or creatures with abilities with triggered abilities when they die like Kokusho, the Evening Star or Lifeblood Hydra.

Cards which can pump the creatures or make them stronger before they get sacrificed like Grafted Wargear or God-Eternal Rhonas are also helpful for this strategy.

The option to win by the activated ability of Jarad is supported by cards like Deathrite Shaman, Loyal Subordinate or Priest of Forgotten Gods.

Since you pretty often kill your own creatures it is furthermore useful to have some synergies with that like card draw, removel and so on due to cards like Deathrender, Skullclamp or Grave Pact.

Alternative win options:

Due to the mass of big creatures Jarad can of course win by normal creature attacks and especially when the graveyard is full of creatures also by Commander damage.

Synergies & Combos:

Jarad, Golgari Lich Lord + Devoted Druid + Quillspike = Instant Win

Gravecrawler + Mikaeus, the Unhallowed + Phyrexian Altar = Infinite Mana

Gravecrawler + Phyrexian Altar + Grave Pact and / or Dictate of Erebos = Mass-Removel of only opponent creatures for 0 Mana

Gravecrawler + Phyrexian Altar + Grim Haruspex, Harvester of Souls and / or Liliana, Dreadhorde General = Infinite card draw for 0 Mana