The previous commit caused air elementals to become almost totally
nonthreatening in the endgame (even the buffed ones on the Plane of
Air). This commit fixes that (whilst still leaving them somewhat
weaker than they were before against characters with good AC), by
doubling the damage of home-plane air elementals.
The damage of the other home-plane elementals was doubled too,
because they were mostly nonthreatening previously. On Fire, this
has no real effect as almost any character would be fire-resistant
by this point. On Earth, it makes the elementals more of a threat,
when they previously weren't.
However, it made Water too difficult (albeit more fun, because it
became important to avoid letting water elementals swam you). As
such, water elementals are made slightly slower to compensate.
(My own playtesting indicates that 6 is slightly too fast, but 4 is
too slow, so I'm hoping that 5 is the correct value.)
253aea33fc