Missile Deflection in Elemental Controls

[Wanderer]

How do you put a Missile Deflection & Reflection Power into an Elemental Control ? Does it need the Costs Endurance Limitation ? May the "Costs Endurance Only To Activate" Limitation suffice ? Otherwise, may a custom "Costs Endurance Per Use" Limitation be used? The ordinary "Costs Endurance" every phase of maintaining the power Limitation seems too expensive for a Constant Power that in some ways works just like an Attack/Instant Power.

[Steve Long]

Of these questions, the Rules FAQ answers the ones that aren't already answered by the rulebook.