Why don't you make it like a building block power?
Here's my Attempt. The numbers would have to be played with.
Gift of Grace [-See Below]
Description: You are guided and protected by your faith.
Musts: Guide my Hand, Righteousness
Skills affected: varies
Effect: When facing a supernatural force who's rolls are being benefitted by a power, you become the equalizer:
[-2]Inhuman Grace:
The great Equalizer: Supernatural creatures do not benefit from inhuman Strength or Speed when targeting or dodging you. If they have Supernatural or Mythic Speed/Str, these powers are down-graded by 1.
Spells and supernatural attacks(such as incite effect) face a 3-shift block. If you have Bless This house, increase the block by +2.
More Potent Prayer:Your conviction is considered infinite for the purposes of modifying skills when using potent prayer.
Smite: You gain +1 to Conviction when using the Final Hour trapping of Righteousness.
[-4]Supernatural Grace:
The great Equalizer: Supernatural creatures do not benefit from Supernatural Strength and Speed when targeting or dodging you. If they have Mythic Speed/Str, these powers are down-graded by 2.
Spells and supernatural attacks face a 5-shift block. If you have Bless This house, increase the block by +2.
More Potent Prayer:Your conviction is considered infinite for the purposes of modifying skills when using potent prayer. Your prayers give an additional +1 (for a total of +2).
Smite: You gain +2 to Conviction when using the Final Hour trapping of Righteousness.
[-6]Mythic Grace:
The great Equalizer: Supernatural creatures may not use Strength and speed powers against you. Spells and supernatural attacks face a 7-shift block. If you have Bless This house, increase the block by +2.
More Potent Prayer:Your conviction is considered infinite for the purposes of modifying skills when using potent prayer. Your prayers give an additional +2 (for a total of +3).
Smite: You gain +3 to Conviction when using the Final Hour trapping of Righteousness.
**Certain attack would get past this. Throwing a car at the person would still hurt like hell. They wouldn't get the +6 weapon damage for, say, Mythic STR, but they'd still get the weapon damage of the thrown car. Or could be pinned under said car with the appropriate maneuver since the power doesn't reduce lifting capacity. It would reduce the bonus to grappling or, possibly, negate the bonus for modifying skills when using Might against said PC.
It also wouldn't prevent supplemental movement from speed powers, but it would negate the bonuses from doing athletic maneuvers against a target (like flanking) or dodging. It may even negate the bonuses it gives to stealth.
I just like doing it this way because it spells it out a bit better.
**The block vs spells and incite probably need to be tweaked. A block isn't as good as a suppression but, still, it's pretty good - especially in an ambush situation. It can get quite high at the Mythic levels especially when paired with Bless This House. It may be too good, but I figured, for 6 refresh, it should be better than your typical dodge.
The other option is to do it like the building block powers: +1/2/3 to dodge supernatural attacks, instead of a straight-up Block...or cap the block at Conviction + bonus from bless this House.