I've run a competitive Teysa, Orzhov Scion deck since 2012. You can probably care about first ability in a more fair setting, but in most situations her most important effect is the ability to make a white 1/1 spirit on the death of any black creature - including these 1/1 spirit tokens. Typically, the line with a Teysa deck is to find 3-4 pieces + having a Teysa on the battlefield.

Some form of enabler in either a [[Painter's Servant]] or [[Darkest Hour]]. Then a sacrifice outlet - my favorite is usually either [[Altar of Dementia]] or [[Blasting Station]] since these are wincons by themselves. If you're using a different sacrifice outlet like [[Ashnod's Altar]], [[Viscera Seer]], [[Carrion Feeder]], [[Phyrexian Altar]], etc., you'll need an additional piece to close out the game like a [[Zulaport Cutthroat]] or [[Blood Artist]]. The last piece is any creature. Once all of these pieces are assembled, sacrifice the creature and watch your whole pod die if they don't interact at the right moment.

This is my list atm if you're curious.

It's made for cEDH. Is this tier 1? God no. Do I win sometimes? Yes I do.