// {2}{B}, {tap}, Sacrifice a blue creature, a black creature, and a red creature:
// Search your library for a card named Prince of Thralls and put it onto the battlefield. Then shuffle your library.
TargetCardInLibrary target = new TargetCardInLibrary(1, 1, new FilterCard(filter));
Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD,
new SearchLibraryPutInPlayEffect(target),
new ManaCostsImpl("{2}{B}"));
ability.addCost(new TapSourceCost());
ability.addCost(new SacrificeTargetCost(new TargetControlledCreaturePermanent(1, 1, filterBlue, false)));
ability.addCost(new SacrificeTargetCost(new TargetControlledCreaturePermanent(1, 1, filterBlack, false)));
ability.addCost(new SacrificeTargetCost(new TargetControlledCreaturePermanent(1, 1, filterRed, false)));