The world of Dirt is a popular place for planeswalkers, for approximately
the same reason that Mexico is a popular place for tourists.  The standard
of living isn't great, and the technology is primitive, but labor is
amazingly cheap.  Wealthy retirees love to come to worlds like Dirt and
carve out their own little empires, playing at war games and the like.
Not all of the major players, though, fall into this category.  Some
are powerful forces fallen on hard times or desirous of solitude who
have retreated into this world to gain power before returning to the
magical equivalent of the fast lane.  The major planeswalkers currently
on the world of Dirt include:

  ARDNEH, the Manipulator.  Ardneh's acts are benevolent; his temples are
devoted to healing, and his clerics are not trained in the arts of war. 
His (or its) specialty is long-distance manipulation; those blessed by
Ardneh seem to act with uncanny luck, bordering on the precognitive.  It
is speculated that Ardneh must have some way to read the future, or at
least to very reliably predict it based on the present.  Ardneh seeks
items, especially mechanical items, of power.  Ardneh's physical form is
uncertain; no indication has ever been given that it is even humanoid. 

  LEONARD, the Healer.  Leonard's clerics are the elite healers of the 
world of Dirt, with Leonard himself being the best healer of all.  He 
uses powerful Old Magic healing (as opposed to what Leonard refers to
as "that pansy wizard stuff"), and under the right circumstances his 
clerics can even raise the dead.  Unlike most planeswalkers, Leonard 
isn't really interested in ancient artifacts or trinkets of power.
He works strictly to make a profit, and he requires all his patients
and clerics to pay in gold.

BECOMING A CLERIC OF LEONARD:
  This costs 2 character picks and an entry fee of 100 gold.  In 
return, a cleric of Leonard can use his Power four times per day.
Each use will heal two HP from an amulet wearer or mend one wound
suffered by a non-Amulet Wearer.  In addition, undead have an aversion
to the Old Magic healing Leonard uses.  Using the Power on one undead
will automatically deal two points of damage.  It can also be used
to frighten away up to 4HP worth of undead.  All but this last use
of the Power requires the cleric to touch the target.
  Each time a cleric uses Leonard's power he must pay 10GP.  This is
automatically removed from his person.

  GAEA, the Environmentalist.  Known as "Karen" to her friends, much to
her irritation. Gaea's goal is to revert civilization into its natural,
pristine, undeveloped state, without any of that messy, polluting
civilization mucking things up.  Her magic is exclusively plant-based and
mostly Old Magic.  She rewards her followers for bringing her rare plants
or fashionable old artifacts.  She also maintains one of the larger
standing armies, for who knows what evil forces may require smiting in the
defense of some random section of forest? 

  SAMARDAS, the Oracle.  Samardas is in charge of most of the divination
that goes on on Dirt.  It requires no artifacts or devices of power from
its followers; instead, it expects them to perform various trivial and
seemingly meaningless tasks as they go about their business.  In return,
it grants access to all sorts of Old Magic divination spells, from
Predict Chance and Detect Treasure all the way to Omni Identify.
Samardas maintains only a small group of guardians surrounding itself and
each of its oracles; in general, it prefers to rely on foreseeing and
avoiding combat.

  TEFERI, the Researcher.  Imagine the greatest blue mage on Dirt,
multiplied by five, with a particular interest in chronology, and you
have a good picture of Teferi.  He rewards his followers for old writings,
tomes, or artifacts, particularly those dealing with time manipulation.
His magic is like wizardly blue magic, but, being mostly External, is much
more powerful.  He has a small group of lesser magicians who assist him
in his dealings with the outside world, and also maintains several small,
magically well-equipped commando-like forces which can strike quickly should
the need arise.  In recent times, they have been employed frequently
against Gaea, who irritates Teferi no end, and they have attempted to
attack Hoki with predictably less than impressive results.

  URZA, the Builder.  Urza is a master artificer; he spends his days
creating ever bigger and better gidgets, and he is happy to teach his
secrets to others.  Most of the artificers and blacksmiths of Dirt are
followers of Urza to some degree.  Urza is interested primarily in
power sources, though, like most planeswalkers, he offers rewards for
devices of unknown technology.  Adventurers who follow Urza are skilled
in the recognition and use of strange artifacts.  Urza keeps a large
staff on-hand to operate and manufacture his various machinery; in
time of war, these can be quickly equipped with some of Urza's more
interesting offensive innovations.

  HOKI, the Trickster.  Hoki delights in annoying others, particularly
other planeswalkers or powerful Dirtian groups with no sense of humor.
His followers have spells of sight, disguise, invisibility, and the like.
Hoki has a weakness for powerful-but-overspecialized Old Age artifacts
(an Amulet of Change, for example, or a Hat of 100x Hair Growth, or
Ring of Increased Buoyancy), but his primary interest is information.
Incidentally, becoming a cleric of Hoki can be difficult, as he moves
around a lot to avoid his victims' retribution.  Hoki has no visible
army; his followers move separately and quietly, spreading chaos among
the ranks of anybody he wishes to harass.

  BJORNEY, the Annoying.  Bjorney, the purple Viking dinosaur demon,
feeds, not on hatred or pain, but on irritation.  He arrived on Dirt
several years ago and immediately adopted the form most suited to
spreading his influence.  Most of Bjorney's followers are other demons
from his plane, but some Dirtians have joined his cause.  Bjorney
maintains a surprisingly well-equipped army for one whose powers lie
so far from direct confrontation.  Amulet Bearers will not voluntarily
enter Bjorney's service.

  DARKONE8888, the Evil.  This creature is the most powerful among several
contenders for Evil Being About To Take Over The World.  It was recently
voted Most Hated Of The Year seven times in succession, and its power has
grown steadily.  It will use anything from zombies to wraiths to nasty
deformed mutant things to acheive its goals, which basically seem to
involve corrupting things and adding to its own power.  Its followers
wield Old Magic which is similar to wizardly black magic but tend to be
physically weak.  Amulet Bearers will not voluntarily enter DarkOne8888's
service.