|A claymore made of weird glowing metal. You wonder whether its radiation will make you grow an extra head.|
+12, +16 claymore
The plutonium sword combines extremely brutal damage output with occasionally awesome miscast effects (irresistible damage, polymorph, confusion, petrification, malmutate) and a nasty magic contamination dose every time you unwield the thing. While it's hard to pass up its staggering damage output, randomly polymorphing opponents will occasionally turn harmless enemies into deadly foes mid-fight. Make sure you have a few scrolls of vulnerability on hand before unwielding it; each scroll you read will reduce your contamination by a small but significant amount.
Prior to 0.12, this sword would curse itself when wielded and contaminated you lightly every turn you held it. Combined with the fact that it did not inflict Transmutation miscast effects, this made it extremely hazardous and much less desirable to use.