Before I get into the hard stuff, there are three homebrew Powers that I want to use here: Undying, Immunity, and All Creatures Are Equal Before Me.
These three powers together do a good job of covering point 2 and 3, as long as the god in question has a decent attack.
UNDYING [-0]
Description: You do not die when you are killed.
Skills Affected: Endurance
Effects:Deathless. Unless utterly destroyed or killed by special means, you can never suffer a fatal wound. No "death" result is ever permanent unless special means are used (as determined by your creature type).
ALL CREATURES ARE EQUAL BEFORE ME [-8]
Description: It doesn't matter how tough they are. You can kill them.
Skills Affected: Fists, Weapons, Guns, Might.
Effects:All Creatures Are Equal Before Me. Your physical attacks ignore all armour and all defensive Powers.
(And Objects) [-1]. When defending against your attacks, all objects have an effective quality rating of 0. Similarly, the difficulty for you to break through any given object or substance is 0.
IMMUNITY [-varies]
Description: You are completely immune to some form of harm.
Note: The cost examples provided here are intended for the hypothetical average game. In unusual games, they may need to be adjusted. For example, the costs here assume that effects like All Creatures Are Equal Before God are supremely uncommon; if this is not true in your game, the more powerful variants of this Power might well be overcosted. Alternately, an an anti-anti-defensive-Power Power could be added to the game. Said more powerful variants are likely inappropriate for some games and should be used with caution. In some rare cases, it may qualify as a Compel when this Power does not apply. Effects that reduce Toughness by one level reduce Immunity to Mythic Toughness.
Skills Affected: Many.
Effects:Immunity. Pick a type of stress. You are immune to that type of stress. This may prevent certain maneuvers and blocks from functioning, at the GM's discretion.
Variable Cost. The cost of this Power depends on the type of stress selected.
- Completely trivial immunities, like drunk-ness or bad smells, are free.
- Very narrow ones, like monkey wrenches or seduction attempts or falling damage, cost 1 Refresh.
- Narrow immunities like poison or acid or magically induced despair cost 2 Refresh.
- Immunity to a single common thing, like metal weaponry or explosions or fear, costs 3 Refresh.
- Immunity to a broad group of things, like the physical attacks of the undead or mental magic, costs 4 Refresh.
- Immunity to an extremely broad group of things, like all magic (including indirect spells) or all unarmed attacks, costs 5 Refresh.
- Immunity to all mental stress with a sizeable weakness, like the attacks of women, costs 6 Refresh.
- Immunity to all physical stress with a sizeable weakness, like cold iron, costs 7 Refresh.
- Immunity to all mental stress with a small loophole, like the attacks of genderless beings, costs 8 Refresh.
- Immunity to all mental stress costs 10 Refresh.
- Immunity to all physical stress with a moderate weakness, like holy stuff, costs 12 Refresh.
- Immunity to all physical stress with a small weakness, like a single legendary weapon, costs 17 Refresh.
- Immunity to all physical stress costs 22 Refresh.
- Immunity to all mental and physical stress costs 30 Refresh.
The issue here is that when two gods fight, the battle will be over way too quickly. One attack and the defending god will be vapour.
Here's my solution:
DIVINE TOUGHNESS [-2/level]
Description: You're ridiculously, insanely, preposterously hard to hurt. Even a god would have trouble wounding you.
Musts: You must have Immunity to all forms of physical and mental attack to take this Power.
Note: You may purchase this Power any number of times. Its effects stack.
Skills Affected: Endurance, Conviction.
Effects:Divine Toughness. Add 1 point of armour and 2 stress boxes to your physical and mental stress tracks. This protection cannot be negated by anything.
That just about covers points 2 and 3. For point 1, which lets you manipulate reality with miraculous power, I'm thinking something like...
MIRACLES [-12?]
Description: You have the power to rewrite reality through sheer divine power.
Musts: You must define a divine domain for yourself in order to take this Power. You should have an Aspect that is related to this domain, and your domain should be about as broad as the thematics of a Sponsored Magic type.
Skills Affected: Conviction.
Effects:Minor Miracles. You may cast any evocation or thaumaturgy spell that fits into your divine domain with evocation's speed and methods. Your power and control are equal to your Conviction, and all spells are treated as Rotes for you. It costs no stress for you to cast up to your base power, and you may cast beyond it at the standard cost of 1 stress per shift.
Major Miracles. You may cast rituals that fit into your divine domain. Once you've gathered enough complexity for a given spell, you need only take a single action to cast it in its entirety. You may gather complexity without having a spell in mind to devote it to, and may store shifts of complexity within yourself to devote to rituals as you please. Each day, you automatically gain stored shifts equal to your Conviction.
MIRACULOUS POWER [-2]
Description: You've got a bit of extra power to boost your miracles with.
Musts: You must have the Miracles power in order to take this one.
Note: You may purchase this Power as many times as you like. Its effects stack.
Skills Affected: Conviction.
Effects:Miraculous Power. Add one to your Conviction skill when using it with Miracles.
Those costs aren't based on anything solid, but these aren't PC powers so that's not a huge deal.
So that's 1-3 more or less covered. I think. Feedback welcome.