Kinzu is a 5 mana, 5-4 flyer. Her only ability apart from flying is a recursion effect that allows you to pay 2 life when a creature you control dies to exile the card from the graveyard and return it to the field as a 1/1 copy of itself with the addition of Toxic 1. She seems to be fairly streamlined in-terms of playstyle, but lets explore those.
With recursion, you can instantly chuck as many ETB and LTB effects in here that you like and get them to trigger twice, providing you have the life to keep up with this playstyle. The toxic on the creature tokens means you can attempt to run it as a poison deck, which would be my choice of the two. But you also get leaves the graveyard triggers, and because of rulings checking how the creature was when it last left the battlefield you can get some interesting things back such as land-creatures, or artifacts that turn into creatures temporarily. Vehicles would be cool, however would still need to be crewed to attack with when a copy is made of them as the effect is printed on the card.
So one interesting way of playing part of this deck is running effects that turn artifacts into creatures until end of turn and then killing them either by sacrificing to an effect or creature or by attacking/blocking with them. There's only a couple of effects for this in mono-black, so not enough to build the whole deck around without tutors specifically for it, but enough to add it in as part of your gameplan. Especially considering it can be used as ways to make copies of ramp/utility artifacts.
If you wanted to, and I would highly recommend it, in mono-colour there is just enough locus and sphere lands to be able to make Monument to Perfection into a creature. If this were to die (through sacrifice as it is indestructible) you could have it come back as a 1/1 with Indestructible, Toxic 9 and Toxic 1. Meaning if you hit anyone with it (Rogue's Passage) it would instantly kill that player due to having 10 poison counters put on them.
You could also look at duplicating proliferation effect artifacts or creatures, after turning the artifacts into creatures through one of the cards above. One that synergizes with the previous card being Throne of Geth allowig you to sacrifice the Monument to Perfection when it becomes a creature and proliferating at the same time.
This is the only card Kinzu has appeared on, introduced in Phyrexia: All Will be One. Kinzu is a phyrexian vampire, part of Vraan's coven. The descriptions found state she was never satisfied killing target one by one, and found ways to use phyresis to perpetuate her killings. Paying life in this regard makes a sense, by using the glistening oil in her she can infect the target and cause it to come back phyrexian. I'm curious as to why it doesn't come back with the creature type phyrexian if this is the case though. https://mtg.fandom.com/wiki/Kinzu https://magic.wizards.com/en/news/feature/the-legends-of-phyrexia-all-will-be-one
Making copies of creatures when they hit graveyard is not unique to only her. A commander that I run is Hofri Ghostforge who does the same thing by bringing them back as spirits and then buffing spirits as well. However causing them to come back specifically as 1/1's and with infect means you can play her not only as "black creature goodstuff soup" and can delve more into a proliferate or toxic/infect stacking playstyle.
RankingsFlavour:
4/5
Mechanics:
4/5
Flexibility:
4/5
Unique:
3/5
Total:
15/20
