Per the Gatherer for The Ozolith:
The Ozolith’s first ability doesn’t move counters off the creature that’s left the battlefield. Instead, it causes you to put a number of counters of each kind of counter that was on that creature onto The Ozolith. [...] Similarly, if the creature has an ability that triggers when it leaves the battlefield that refers to the number of counters it had, that ability will use the number of counters that were on the permanent, even if The Ozolith’s first ability resolves first.
This would mean that if a Vastwood Hydra dies, both The Ozolith's and Vastwood Hydra's abilities would produce counters, correct? I feel like this is similar to how this thread scenario works with Skullbriar, the Walking Grave, but wanted to make sure.
The weirder issue I've come across has to do with this interaction mixed with Hapatra, Vizier of Poisons and/or if The Ozolith has become a creature somehow. From the Gatehrer for Vastwood Hydra:
In some unusual cases, Vastwood Hydra will have enough -1/-1 counters put on it to make its toughness 0 or less. If this happens, the ability will still distribute a number of +1/+1 counters equal to the number of +1/+1 counters on Vastwood Hydra before the -1/-1 counters were put on it.
Since the state-based actions of the creature having 0 (or less) toughness and the +1/+1 and -1/-1 counters annihilating each other occur at the same time, the Vastwood Hydra sees that it had +1/+1 counters on it when it died and so it's ability puts those counters on other creatures. Is this the same thing that The Ozolith sees, and if so would it have the +1/+1 and -1/-1 counters put on it? If yes and it's somehow a creature at the time, Hapatra would get another snake trigger, and if more -1/-1 counters were put on it than +1/+1 counters it already had to the point that it's toughness was zero, The Ozolith would then also die, correct?
Side note: I've seen people have confusion about the phrasing on The Ozolith, and I would think changing the phrasing from "put those counters" to "put the same counters" would fix a lot of the understanding issues. Is there a rules-based reason they didn't phrase it this way? But I digress...
Your question seems buried in a lot of pointless text.
If I understood your question then yes you will "double up" on counters from vastwood hydra dying while you have the ozolith.
For your second questions it is again yes. If the ozolith is a creature when its first ability resolves and the creature that left had -1/-1 counters then it will get those counters and you will get a snake from hapatra.
About the ozolith getting both types of counters when a creature with + counters dies from getting - counter. The ozolith gets all the counters and then they are promptly annihilated.
Yes, an animated Ozolith would die if it receives enough -1/-1 counters to lower its toughness below one.
Yes, even a non-animated Ozolith would have +1/+1 counters and -1/-1 counters eliminate each other:
122.3. If a permanent has both a +1/+1 counter and a -1/-1 counter on it, N +1/+1 and N -1/-1 counters are removed from it as a state-based action, where N is the smaller of the number of +1/+1 and -1/-1 counters on it. See rule 704.
I would think changing the phrasing from "put those counters" to "put the same counters" would fix a lot of the understanding issues. Is there a rules-based reason they didn't phrase it this way? But I digress...
A very good question. Even the rule about moving counters does not actually state that old counters are to be eliminated while new, identical counters are to be created:
122.5. If an effect says to “move” a counter, it means to remove that counter from the object it’s currently on and put it onto a second object. (...)
The Ozolith’s first ability doesn’t move counters off the creature that’s left the battlefield. Instead, it causes you to put a number of counters of each kind of counter that was on that creature onto The Ozolith. [...] Similarly, if the creature has an ability that triggers when it leaves the battlefield that refers to the number of counters it had, that ability will use the number of counters that were on the permanent, even if The Ozolith’s first ability resolves first.
This would mean that if a Vastwood Hydra dies, both The Ozolith's and Vastwood Hydra's abilities would produce counters, correct? I feel like this is similar to how this thread scenario works with Skullbriar, the Walking Grave, but wanted to make sure.
The weirder issue I've come across has to do with this interaction mixed with Hapatra, Vizier of Poisons and/or if The Ozolith has become a creature somehow. From the Gatehrer for Vastwood Hydra:
In some unusual cases, Vastwood Hydra will have enough -1/-1 counters put on it to make its toughness 0 or less. If this happens, the ability will still distribute a number of +1/+1 counters equal to the number of +1/+1 counters on Vastwood Hydra before the -1/-1 counters were put on it.
Since the state-based actions of the creature having 0 (or less) toughness and the +1/+1 and -1/-1 counters annihilating each other occur at the same time, the Vastwood Hydra sees that it had +1/+1 counters on it when it died and so it's ability puts those counters on other creatures. Is this the same thing that The Ozolith sees, and if so would it have the +1/+1 and -1/-1 counters put on it? If yes and it's somehow a creature at the time, Hapatra would get another snake trigger, and if more -1/-1 counters were put on it than +1/+1 counters it already had to the point that it's toughness was zero, The Ozolith would then also die, correct?
Side note: I've seen people have confusion about the phrasing on The Ozolith, and I would think changing the phrasing from "put those counters" to "put the same counters" would fix a lot of the understanding issues. Is there a rules-based reason they didn't phrase it this way? But I digress...
If I understood your question then yes you will "double up" on counters from vastwood hydra dying while you have the ozolith.
For your second questions it is again yes. If the ozolith is a creature when its first ability resolves and the creature that left had -1/-1 counters then it will get those counters and you will get a snake from hapatra.
About the ozolith getting both types of counters when a creature with + counters dies from getting - counter. The ozolith gets all the counters and then they are promptly annihilated.
Yes, even a non-animated Ozolith would have +1/+1 counters and -1/-1 counters eliminate each other:
A very good question. Even the rule about moving counters does not actually state that old counters are to be eliminated while new, identical counters are to be created:
RULES OF MAGIC :
http://magic.wizards.com/en/game-info/gameplay/rules-and-formats/rules