Tidal Warrior and Non-Basic Lands

[(nameless one)]

Can anyone help me with the following scenarios:

1) I have an active Tidal Warrior. My opponent has an active Wasteland and activates it to destroy my Mutavault. Can I respond to that by turning the Wasteland into an Island?

2) I have an active Tidal Warrior. My opponent has an active Wasteland and activates it to destroy my Mutavault. Can I respond to that by turning my Mutavault into an Island?

3) I have an active Tidal Warrior. My opponent has an active Academy Ruins and activates it to return an artifact on top of his library. Can I respond to that by turning the Academy Ruins into an Island?

4) When is the right time to turn a man-land such as Mishra's Factory into an Island? Should I turn the man-land into an Island before or after he declared the activation of Mishra's Factory?

5) Does Darksteel Citadel lose indestructability when you turn it into an Island with Tidal Warrior?

6) Are there any known tricks that you can pull off with Tidal Warrior?

Thanks!

[Anusien]

Can anyone help me with the following scenarios:1) I have an active Tidal Warrior. My opponent has an active Wasteland and activates it to destroy my Mutavault. Can I respond to that by turning the Wasteland into an Island?

No, sacrificing it is part of the cost.

2) I have an active Tidal Warrior. My opponent has an active Wasteland and activates it to destroy my Mutavault. Can I respond to that by turning my Mutavault into an Island?

Tidal Warrior, like Blood Moon, does not change super types. You can respond to that by changing your Mutavault into an Island, but it will still be destroyed.

3) I have an active Tidal Warrior. My opponent has an active Academy Ruins and activates it to return an artifact on top of his library. Can I respond to that by turning the Academy Ruins into an Island?

Yes, but the ability will still be on the stack and still resolve.

4) When is the right time to turn a man-land such as Mishra's Factory into an Island? Should I turn the man-land into an Island before or after he declared the activation of Mishra's Factory?

No matter when you turn it into an Island, he can activate it in response and it will still be a 2/2 creature. Just without the pump ability. Same thing if you change it into an Island with the animation on the stack.

5) Does Darksteel Citadel lose indestructability when you turn it into an Island with Tidal Warrior?

Yes

6) Are there any known tricks that you can pull off with Tidal Warrior?

Turning things into Islands.

[Forbiddian]

Yes
Turning things into Islands.

XD