Team Unicorn is proud to have 4 World Champions. No other brand has more Champions or more Championship victories. As World Champions they demand the very best. This is what they use.
Why tungsten for darts? The UniBoffin explains:

Tungsten is Swedish for "heavy stone" and was well-named, being one of the densest substances known. The pure metal weighs around 19gms/cc, and although this reduces slightly when it is combined with small amounts of, eg, nickel to produce a more workable material, the resultant alloy. will still be 50% denser than lead and maybe twice as dense as brass or steel.

Dart barrels in high percentage tungsten alloy can hence be far thinner for a given weight and length than ones made from more traditional materials, which obviously helps to avoid bed-blocking and allows three of them to nestle nicely in the treble 20 with room to spare. Another advantage here is tungsten's exceptional hardness, which means those nestling barrels will be resistant to damage.

To improve on tungsten as a dart barrel material is theoretically possible (a case could be made for, eg, platinum/iridium at over 21gms/cc), but in practical terms it's pretty much the ultimate!

BOB ANDERSON. WORLD CHAMPION 1988.