Bashanishu is a Challenge Achievement completed by hitting the rare, unique Fallen Shaman Bashiok with Rakanishu's Blade. In a cooperative game, it is only granted to players that have directly hit Bashiok with the blade, not all players in the party. Upon completion, a new banner accent will be available.
There are two overall steps to completing the achievement: Obtaining the blade, and hitting Bashiok with it.
Obtaining Rakanishu's Blade[]
Rakanishu's Blade is obtained by completing the Shrine of Rakanishu event, which does not always appear. This is probably easiest in Adventure Mode. There are two alternative sub-strategies: Look for the Shrine of Rakanishu bounty appearing on the map and restart the game until it does, or directly looking for the Shrine in the Dahlgur Oasis and restart the game until it does.
Once the Shrine is found, complete the event and look for the Blade to drop. It is unconfirmed whether its drop rate is 100%. If it doesn't appear, restart the game and try again.
Hitting Bashiok with the blade[]
Once the blade is found, the primary concerns are finding Bashiok, and ensuring you can hit him with the weapon before he is killed in some other way.
- Set the difficulty to a level where the movement-focused, non-combat build suggested here does not make travel in the Dahlgur Oasis dangerous.
- Equip Rakanishu's Blade. Unequip all other weapons (such as in the offhand slot) and any gear with Thorns. Just in case.
- Dimiss any Followers.
- Ensure skill selection includes no pets or other entities that attack automatically. Ideally, use a fully movement-focused skill and item selection.
- Set one of the mouse button skill selections to be a basic attack by dragging any equipped skill out of the slot. Elective Mode must be turned on in game options. This step is probably unnecessary, since even a skill-based attack should work.
To find Bashiok, once again there are two alternative sub-strategies: Look on the map for a bounty to kill Bashiok, or search the Oasis for him. In either case, restart the game until successful. Both take a long time, as the bounty is only one among many "kill bounties", but Bashiok himself is rare and the Oasis is large. Bashiok is a unique Fallen Shaman, but it is possible for him to appear with other unique Fallen Shaman in the zone, so most of the zone needs to be covered to be sure.
Once he's found, hit him with the basic weapon attack or any other direct attack skill - achievement obtained.
