The death won't be counted as one, as the creature regenerates its entire health at that point. X depends on the creature's casting cost, but will not cost more than 10
. The spell should cost 4
, because it's a bit situational.
As to Ambush, I think Ambush is just fine the way you suggested, OT. This ability would rather be used for small creatures, but will only reveal its true power when connected with Fractal or TU. It'd be interesting if you could apply it to all creatures without an active ability. The ability should not just set the attack to 0, it should include buffs - including debuffs - so a blessed creature with the Ambush ability will have 3 attack instead of 0 as a base.
Phasing looks okay.
Debuffs can basically kill creatures, so we should consider that when making up numbers for spells. The cost should depend on the power of the effect, and attack-decremention should cost less than health-decremention. The question is, should debuffs be able to set a creature's attack to negative values? However, I think this can be an ability as well, but shouldn't be as strong as the spells. I suggest an ability should only debuff both 1 attack and 1 health as a maximum, and that there should be buffs as well, just like Blessing.
My suggestion for Debuff:
Debuff(-N|-M):X [N=attack, M=health, X=cost] and [X=(N+1/2)+(N+M*2)-K; (rounded down)]
Debuff(-2|0) would therefore cost 2 quanta;
Debuff(0|-2) would therefore cost 4 quanta;
Debuff(-1|-1) would therefore cost 3 quanta;
Debuff(-4|0) would therefore cost 5 quanta;
K is the constant. K is 1 for an ability and 2 for a spell (though it cannot reduce the cost to 0). Additionaly, this formula can be used for buffs as well, just that K for a spell would be 3.
