Example Powers 11: Intangibility

Kitty Pryde walking through walls, vampires turning into mist, sci-fi tech that makes things "out of phase" with the rest of the universe, and other powers that allow similar "here but not solid" abilities are covered by this power. 

Intangibility: This power allows its user to become ethereal and insubstantial. The caster gains a +1 bonus on a basic success and for each point of Advantage on the casting roll. This bonus is applied to all difficulties to affect the character physically (such as attacks that target Toughness and Defense) as well as to the difficulty of all the user's attempts to physically affect others. The bonus is also applied to the user's attempts to move across or through barriers (by simply walking through them instead of climbing, squeezing, or breaking through).

• Among the Necromancers of Taj Neroth, only the followers of Lopcilthoth know this power. They call it the “Night Shroud” spell. It causes the caster's body to become a black silhouette lit with tiny stars like a section of night sky. The caster's actual body is somehow condensed into the tiny stars although they still occupy the same space and possess the same mass. Any physical blow that misses one of the stars will pass through them harmlessly.
• The Elemental Mages know this power as the spells “Cloud Walker”, “Flesh of Water”, “Sand Form”, and “Firebody”. All four are Scene spells that alter the caster's body to take on the textural qualities of an element to allow them to slip through narrow gaps or ignore less-than-catastrophic physical attacks against them.
• Aetheric Engineers have developed Phase Shifters, devices that cause the target to shift slightly out of phase with normal matter which allows them to pass through solid objects like a ghost. At low power levels, the user of a Phase Shifter could slowly push through a solid wall and meet the resistance of thick mud rather than a solid surface. At more intensive energy levels, the user of a Phase Shifter could run through a solid wall without slowing down. Phase Shifters are generally very rare devices but two of the more commonly seen varieties are the Ghost Intrusion System and the Houdini Field. The Ghost Intrusion System is a Scene device mounted on a belt or chest harness; spies and elite commando teams use it to infiltrate fortified areas or for boarding actions. The Houdini Field is a smaller Instant device usually hidden in a thick boot heel or large wristwatch; it is favored by spies and high-class criminals who use it to escape from holding cells or slip out of handcuffs or other restraints.
• The Dai Zha and Ma Quy templars do not use this power. They have a reputation for being difficult to capture or restrain, but their ability to overcome such things is due to their cleverness and resourcefulness rather than any sorcery.
• The Tyrian Brotherhood do not use this power. They overcome barriers and resist attacks though more traditional methods: being strong enough to batter down doors and tough enough to take a beating (although they may use special prayers to enhance those traits).