That's okay. It's not a simple game and here I am trying to explain this card without giving you context. Let me elaborate.
When the second effect is activated, the keyrune becomes an Artifact Creature. Think of it as a robot made and powered with magic instead of technology. It's "living" in the same way that R2-D2 is "living" - an artificially created being with some level of free will, though in this case it wouldn't have much and would be very open to whatever orders its controller gives. It's only "alive" while the effect that makes it an Artifact Creature is active; at all other times it's an inanimate object with no awareness or volition.
The first ability requires that the keyrune be "tapped", which prevents it from doing anything that requires it to be "untapped" until the start of its controller's next turn, when it untaps by itself. Doing so results in it generating one unit of either red or green magical energy, or "mana", which dissipates harmlessly if not used within a brief period of time; there is no way to bank this mana, thus the keyrune can only ever be responsible for up to one mana being available at a time. Since the ability that makes it a creature requires two mana (one red and one green) to activate, the keyrune itself cannot generate enough mana to turn itself into a creature. In the event that Domri gained access to an additional source of mana, such as via another item drop, the keyrune's requirement that it be tapped to generate mana would mean that if it were turned into a creature that creature would be tapped. A tapped living creature is something akin to being asleep or otherwise unable to act. A tapped artifact creature like what the keyrune becomes is something like being powered-down; it can't attack, defend, or create more mana, and will in fact stop being a creature before it untaps. It would require Domri to have access to a third source of mana to be able to use the keyrune as a creature that can fight. Preventing that simply requires him to never have access to more than two mana, which I can promise that I can ensure (outside of 4th wall, but then that's 4th wall). Since the no-powers rule is still in effect, Domri wouldn't be able to use the keyrune's mana for magic himself, only for powering the effects of artifacts, which he currently has none.
What I'm hoping for is for Domri to have the keyrune with its powers intact; he would be able to tell that it's generating mana (maybe with it glowing as it does - it's not clear or consistent exactly what tapping for mana looks like) and if a situation came about where he had access to a second mana it would become an immobile creature, but he couldn't actually do anything with it that would affect the game in any way other than allowing him to show off (at best).
And I realize after typing this that I've written a lot of text for the sake of a single joke that will likely amuse no one but myself.
no subject
When the second effect is activated, the keyrune becomes an Artifact Creature. Think of it as a robot made and powered with magic instead of technology. It's "living" in the same way that R2-D2 is "living" - an artificially created being with some level of free will, though in this case it wouldn't have much and would be very open to whatever orders its controller gives. It's only "alive" while the effect that makes it an Artifact Creature is active; at all other times it's an inanimate object with no awareness or volition.
The first ability requires that the keyrune be "tapped", which prevents it from doing anything that requires it to be "untapped" until the start of its controller's next turn, when it untaps by itself. Doing so results in it generating one unit of either red or green magical energy, or "mana", which dissipates harmlessly if not used within a brief period of time; there is no way to bank this mana, thus the keyrune can only ever be responsible for up to one mana being available at a time. Since the ability that makes it a creature requires two mana (one red and one green) to activate, the keyrune itself cannot generate enough mana to turn itself into a creature. In the event that Domri gained access to an additional source of mana, such as via another item drop, the keyrune's requirement that it be tapped to generate mana would mean that if it were turned into a creature that creature would be tapped. A tapped living creature is something akin to being asleep or otherwise unable to act. A tapped artifact creature like what the keyrune becomes is something like being powered-down; it can't attack, defend, or create more mana, and will in fact stop being a creature before it untaps. It would require Domri to have access to a third source of mana to be able to use the keyrune as a creature that can fight. Preventing that simply requires him to never have access to more than two mana, which I can promise that I can ensure (outside of 4th wall, but then that's 4th wall). Since the no-powers rule is still in effect, Domri wouldn't be able to use the keyrune's mana for magic himself, only for powering the effects of artifacts, which he currently has none.
What I'm hoping for is for Domri to have the keyrune with its powers intact; he would be able to tell that it's generating mana (maybe with it glowing as it does - it's not clear or consistent exactly what tapping for mana looks like) and if a situation came about where he had access to a second mana it would become an immobile creature, but he couldn't actually do anything with it that would affect the game in any way other than allowing him to show off (at best).
And I realize after typing this that I've written a lot of text for the sake of a single joke that will likely amuse no one but myself.