> Your Guy (Air)
> Str: 15
> Con: 20 (+2 Water)
> Agl: 10
>
> Their Guy (Water)
> Str: 15
> Con: 20 (+2 Air)
> Agl: 10
>
> By my calculations, neither character can ever hit the other for any damage. Would this battle go on forever?

Not quite. What happens is this:

Regular attack damage is calculated: 15 STR - 20 CON results in one hit point of damage per 7 blows.

Then elemental bonuses are factored in:

In rounds with 0 hits of damage so far, total damage is 0 - 2, which means one hit of damage per 4 blows.

In rounds with 1 hit of damage so far, total damage is 1 - 2, which means one hit of damage per 3 blows.

So now let's look at when the blows actually hit. The numbers across represent the blow number (last digit only), starting with the first. The numbers on the second line indicate the number of hits of damage (0 or 1) done during that round:

1234567890123456789012345678901234567890...
0001000100010001000110010000000100010001...

In other words, if the blow number is divisible by 7, it must also be divisible by 3 to hit. If it's not divisible by 7, then it must be divisible by 4 to hit. (Note the key blows #21 [divisible by 7 and 3 but not 4], and #28 [divisible by 7 and 4 but not 3].)

At least, that's how I *think* it works.

It's academic, in any case, since, starting with tournament #2, elemental bonuses will be applied *before* the boost-to-zero calculation, making them simple boosts to normal attack and defense power.