A simple achievement which you can get by feeding materials to your weapons. I wanted to share a nice guide I found by FuzzyfingerGaming over on Youtube.
In his guide, you can get a high level Ashura early in the game. By following his Youtube tutorial, I was able to get this achievement.
Tips from me:
I farmed 7 Flame Shards which are dropped by the bombs on the Hunter's Hideaway quest. This item gives you 7% Flame Elemental which is needed to "feed" the bar towards the required 53%. I then topped it up with some Strength and Vitality Boosting stats such as the Octolegs from the Baleful Bandersnatch quest to take it to level 30 and remodel. From there, I continued to farm more Octolegs to take the Ashura to level 50.
Also, I liked these two farms as it awarded some nice KW and EXP which is useful to progress through the campaign.
Hope this helps someone!