MTG Salvation

No. While Syr Gwyn will deal combat damage twice, she is still only attacking once. To attack is to be declared as attacker during the declare attakcers turn based action, which you do only once per combat.

Do note, that this also means, that you draw the card(s) in the declare attackers step, before blockers are declared.

Yes. A permanent entering with counters counts as putting those counters on it.

You cannot assign its combat damage to the player/planeswalker it attacked, because it is blocked. A blockecd attacker that has no creatures blocking it (anymore) deals no combat damage. Unless it has trample, it which case you can assign excess damage to the player/planeswalker. If multiple creatures blocked the double striker, then yes, you can assign the second strike's damage among ITS remaining blockers. You cannot let it deal its combat damage to a creature that is not blocking it. (Note, that you do not have to hit only one creature with the first strike. You can reach as far into the comga line of death as your attacker's power allows. It is also possible to add damage from the first strike and damage from the second strike to kill a creature.)

Yes, that works for the reasons given. You have the combat damage step and the end of combat step to do your shennanigans. (For example, there could be an end of combat trigger from a creature that you don't want to happen, so you do this in the combat damage step. Otoh, there could be an end of combat trigger from a creature, that you do want to happen, but also want that creature gone, so you do it in the end of combat step.)

The aura adds an activated ability to the land. Since both that and the inherrent mana ability of the land are activated abilities that require tapping the land, you can only pay for one with one tap. So you have to choose between mana or damage.

Now if it were to add a triggered ability, then you could get both by tapping the land for mana, and getting the damage from the trigger. But this is not how Noxious Field works.

Also note, that enchanting another player's land with that aura gives them, as the controler of the land, control over the damage ability. You can't tap their land like that.

Also, since the Druid stops being a creature, it can be used even on the turn it enters the battlefield as summoning sickness does not affect non-creature permanents.

The Disenchant cannot even be cast on the Asceticism due to shroud granted by Sterling Grove.

611.3a A continuous effect generated by a static ability isn’t “locked in”; it applies at any given
moment to whatever its text indicates

611.3c Continuous effects that modify characteristics of permanents do so simultaneously with the
permanent entering the battlefield. They don’t wait until the permanent is on the battlefield and
then change it. Because such effects apply as the permanent enters the battlefield, they are
applied before determining whether the permanent will cause an ability to trigger when it enters
the battlefield.

And just to prevent discussion on wether having shroud is a characteristic:

109.3. An object’s characteristics are name, mana cost, color, color indicator, card type, subtype,
supertype, rules text, abilities, power, toughness, loyalty, defense, hand modifier, and life modifier.
Objects can have some or all of these characteristics. Any other information about an object isn’t a
characteristic. For example, characteristics don’t include whether a permanent is tapped, a spell’s
target, an object’s owner or controller, what an Aura enchants, and so on.

Protection does four specific things for the protected permanent or player, which you can remember by DEBT:

D amage from a source with the stated quality will be prevented (unless damage can't be prevented for some reason)
E nchanting/equipping/fortifying will not be possible (so no enchantment/equipment/fortification can get attached to it)
B locking the protected creature is not possible by creatures with the stated quality
T argeting is not possible by sources with the stated quality

Note, that protection is not a catch-all. Untargeted destruction like with Wrath of God, forced sacrifice like with Soul Shatter, negating damage prevention like with Questing Beast, etc. can still get around protection.

In order for your 9/9 to live, you have to put the deathtoucher first in its damage assignment order. That way, you can deal 5 (plus up to 4 more) damage in the first combat damage step to it, which will result in it being destroyed before it can strike in the second combat damage step.

Yes. The Prophet's ability will only trigger if it is on the battlefield when your upkeep begins, and you have to have the city's blessing. The blessing, once achieved, will stay for the rest of the game. But there is nothing inherently linked to it, it's just a marker, that you have achieved a certain game state in this particular game, to be referenced by spells and abilities.

Quote from Selvaxri »

I've always wondered if there's a Haste mechanic, why isn't there ability to slow down creatures and such, like Orim's Chant?

Well, while not a keyworded mechanic, Urabrask the Hidden is the (current) solution for such a mechanic.

Only if the attacker has trample or some other ability to allow for such a thing. Just removing the blockers won't do. If an attacker finds itself blocked with no creatures blocking it (anymore) it will simply assign and deal no combat damage.

509.1h An attacking creature with one or more creatures declared as blockers for it becomes a
blocked creature; one with no creatures declared as blockers for it becomes an unblocked
creature. This remains unchanged until the creature is removed from combat, an effect says that
it becomes blocked or unblocked, or the combat phase ends, whichever comes first. A creature
remains blocked even if all the creatures blocking it are removed from combat.

510.1c A blocked creature assigns its combat damage to the creatures blocking it. If no creatures are
currently blocking it (if, for example, they were destroyed or removed from combat), it assigns
no combat damage. If exactly one creature is blocking it, it assigns all its combat damage to that
creature. If two or more creatures are blocking it, it assigns its combat damage to those creatures
according to the damage assignment order announced for it. This may allow the blocked
creature to divide its combat damage. However, it can’t assign combat damage to a creature
that’s blocking it unless, when combat damage assignments are complete, each creature that
precedes that blocking creature in its order is assigned lethal damage. When checking for
assigned lethal damage, take into account damage already marked on the creature and damage
from other creatures that’s being assigned during the same combat damage step, but not any
abilities or effects that might change the amount of damage that’s actually dealt. An amount of
damage that’s greater than a creature’s lethal damage may be assigned to it.

That'S what we are here for, if it is a rules related question. But please make a new thread if it isn't directly related to what was asked and answered in this one. For non-rules questions try asking in the appropriate forum instead.

Protection helps against four specific things (DEBT):
D amage to the object is prevented
E nchanting/equipping is not possible
B locking is not possible
T argeting is not possible

Protection is taken into account constantly at every time. Whenever something tries to do one or more of the four things, protection applies and stops it. In regards to abilities, the game looks at the source to determine if protection applies.

So in your first scenario, your Angelic Curator will not be tapped by Abyssal Hunter due to having become an illegal target. And since the ability doesn't resolve, the damage prevention doesn't even matter.

In your second scenario, you cannot target the Curator with the Souleater's ability due to protection from artifacts. To do so, you have to FIRST turn the Souleater into a nonartifact. Afterwards you can target the Curator at your leisure.

You return Zada from your graveyard to your hand when Disentomb resolves. That's all. Zada's triggered ability can function on the battlefield, and since it doesn't dspecify otherwise, it ONLY functions while Zada is on the battlefield.

113.6. Abilities of an instant or sorcery spell usually function only while that object is on the stack.
Abilities of all other objects usually function only while that object is on the battlefield. The
exceptions are as follows:
[...]

None of the exceptions apply.