This achievement can either be achieved
through normal progression, or you can get it
very easily in split screen.*
*It appears that this achievement cannot actually be unlocked in Scenario mode, leaving you to do either the method outlined here or to try your luck in multiplayer, as I would assume it can be done online through either boosting or normal play if it can be done in split-screen.
The easiest way I found based on the skills I already had was to create a two-school arsenal which contained the skills Lightning speed (+5) and Speed Up (+2), filling the rest of the slots with aura particles.
Then go into split screen, and use both of the skills, which got my movement speed up to +7.
If you haven't got either of these skills, you can either try and purchase them from the store if they pop up or by trying your luck with junk packs. Remember that the skills I used are only one way of doing this, so just use whatever skills you already have that when combined, give a buff of greater than +5 or a debuff lower than -5.
If you want to check out the full list of skills go here:http://phantomdusted.com/pd_skills.htm
To set up a game for split screen, go to multiplayer and then split screen. From here press the menu button on the second controller and choose quick deck 1. When you have got your arsenal sorted, go to start game and select standard battle.