Wyrmbane

An enchanted lance which grows more and more powerful every time it inflicts a killing blow on a dragon.

A scale-covered lance

Base stats: 8 damage, +4 accuracy, 11 delay
Enchantment: +9, +6

Dragon slaying brand
+5 AC
rF+
rPois
Allows Berserk

If a dragon slaying-vulnerable target is killed by the base damage of this weapon, it will gain +1, +1 enchantment up to the HD of the dragon killed. Though Wyrmbane can be thrown like a spear, killing a dragon by doing so will not raise its enchantment.

To better illustrate this ability, here are some examples:

• If you kill a standard fire-breathing dragon (HD 12) with the basic +9, +6 Wyrmbane, it will become +10, +7 (both enchantments were under 12, so both were raised by 1).
• If you then use Wyrmbane to kill a lindwurm (HD 9), Wyrmbane will become +10, +8 (the to-damage enchantment was raised by 1, but the to-hit enchantment was already greater than 9).
• If you then use Wyrmbane to kill a steam dragon (HD 4), Wyrmbane's enchantment will not change (the dragon was too weak to boost the enchantment).

The maximum enchantment Wyrmbane can gain this way is +18, +18, though there are draconic monsters with higher HD. Even if you manage to kill something like the Serpent of Hell (HD 20) or Tiamat (HD 22) with Wyrmbane, its enchantment won't increase past +18, +18.

Desirability

A +18 Wyrmbane is a very respectable weapon indeed, given that it provides a high amount of damage at a fairly fast speed (5 min delay). In terms of raw damage it will outperform a demon trident of freezing fairly well, and it isn't too far behind a branded bardiche while requiring considerably less skill investment to start using; it also allows you to use a shield. Moreover, it provides a number of useful intrinsics, many of which can help you survive the dragons you'll have to kill in order to improve the weapon.

The downside is, one must be willing to invest the time spent killing stronger and stronger dragons with it in order to make it a truly competitive weapon. Getting Wyrmbane up to +12 isn't that hard, as you only need to kill fire or ice dragons to get that far, and reaching +14 from fighting storm dragons isn't too much more difficult (provided you have electricity resistance). Past there, though, you'll have to start killing things like shadow dragons, golden dragons, or bone dragons, none of which are particularly easy to fight.

The Crypt and Hell tend to send plentiful skeleton and zombie dragons at you, including some of the highest HD ones. These undead foes are much easier than their living brethren, and count as dragons for the purpose of improving Wyrmbane.