A Panoply of Portal Problems

[Wavefunction]

Hi all,

Got a few questions relating to Warp (Area Effect, 2 yards, +50%; Cancellation, +10%; Extended Duration, Permanent, +300%; Ranged, +40%; Tunnel, +100%) (just to cover the basics of the build):

What kind of Power Defense would you use to stop an attack by opening a portal in front of it? Assuming it would be a Power Defense of course, normal Warp uses different rules for dodging attacks than a Power Dodge. How about using aforementioned defense multiple times per round? What about doing that at no penalty?

If you did block an attack with a tunnel, how would you represent arranging the portal 'mouth' so that the attack hits the person attacking you, or someone else for that matter?

What about the ability to close a portal whilst someone's arm (or head, weapon, lamppost, etc.) is stuck through it, severing it?

Finally, in Pyramid: Infinite Worlds 2, Lord of Your Own Domain the Tunnel enhancement is given another level to permit multiple simultaneous Tunnels. How would you open several tunnels at once? I guess there's limited Compartmentalized Mind, but are there any other options.

I have some idea on how to build the above abilities, but I'd like to hear other people's views.