Kill 5 guards in 5 seconds using only your hidden blades. (20 G)

It is best to combine this with a Smoke Bomb. You must select your hidden blades and cannot use any other weapon. You have to do this extremely quickly. Killing 2 guards at once will be required. You must kill 2, kill another 2, then kill the last 1. Almost all guards travel in 4, so you must find an area with more or lead them with cherry bombs. Throw a smoke down and start assassinating.

You can try this in any heavily populated guard area or if you want fast access, just go to DNA Sequence 4 Memory 1 and get to the courtyard area that has tons of guards.

A good method instead of using Smoke Bombs is to use Poison Bombs. You can still get your kills before they die, plus you can see what is going on. Load the above sequence, get on the roof, and thrown down a cherry bomb. Now you can throw down poison and leap and assassinate, then assassinate the remaining. You will get de-synced but that is perfectly fine.