If by OP you mean overpowered (i.e. powerful), you'll have to find a monster spawner in a dungeon. When you have found one, excavate the area four blocks around it, and fully light the area. Then build an "xp grinder" around it using whichever tutorial from YouTube strikes your fancy (there are lots of different designs).
Then build an enchanting table along with 30 bookcases, and construct your enchanting area (again, according to your favourite YouTube tutorial).
You'll need to idle near the grinder, occasionally killing the mobs you spawn, for about 2-1/2 hours per enchantment attempt. Every time you reach level 50, make a diamond sword, and enchant it at level 50 on your enchanting table. Getting the table to show you a level 50 enchantment can take up to 300 placements and removals of the sword from the table.
When you enchant the sword, see if it has a set of enchantments that satisfies you; otherwise, try again.