Create a class!

[eastless]

That's what I came up with.

4 tier classes:

Chieftain
GRIM: Death Protections stacking. Manacost increases arithmetically (8/10, 16/20...). Level up or triggering resets cost.
IMMORTAL: Max health lowered.
HEAVY HAND: Always strikes last in combat, pierces physical resistance (RBS effect).

Burglar
SNATCHER: Every kill grants +1 gold (Gloves of Midas effect).
MALEDICTORY: Cursing attack.
DUMB: -5 max mana.

Seraph
FAITHFUL: Piety generation doubled. Penalties doubled too.
NIMBUS: Tripled sight radius.
FIERY: Burning stack on attack (Whurrgarbl effect).

Arcanist
MORE POWER-HUNGRY: 1 level of manasteal. (Monsters get mana bar of 10 points. Attacking a monster refills your mana (1 x your level).)
MASOCHIST: Taking damage refills mana (permanent Schadenfreude).
FULL OF THOUGHTS: -5 hp per level. +10 max mana.

Possible conversion bonuses for new monster classes:
Zealot: +20 piety for every 100 CP;
Gold Blob: +10 gold for every 100 CP;
Archdruid: +1 learning buff for every 150 CP;
Golem: +5% resists, +1% max resists for every 100 CP (cannot worshipping gods );
Naga: +1 weakening blow for every 100 CP;
Ent: +1 damage reducing for every 50 CP;
Animated Armour: +1 DP for every 100 CP;
Shifty: +5% dodge for every 100 CP.

And one more class, but I'm not sure...
Exalted: starts at L10. Map preexplored. Cannot regenerate health or mana. Every 200 CP lowers level by 1.

I have not used search, hope to come up with anything new.

[eastless]

Three more monster classes:
Cave Snake: getting hit spawns Snake (First Strike, NO No Experience) equal to your level. Every 100 CP also spawns Snake.
Minotaur: 50% knockback, berserks at 50% hp, every 120 CP increases berserk treshold by 5%.
Shade: -5 hp per level, 30% resists, cannot worshipping gods, regenerates same as Vampire (getting exhausted below max hp), lifesteals in Shade/Vampires style (drains hp from revealed monsters, overwhelms enemies lifesteal!), starts at 30%, every 100 CP increases lifesteal by 5%; GETTING HIT MAKES YOU BLINK!