Graphic5 
Simple plugin to connecting attributes. If you have a lot of attributes (it’s very often after CSV product/combinations import) – this plugin is good for you. For example – If you have the same color with two diffrent name (eg. red, dark red, real red, Red) – you can easy connect them with this plugin.
How it works? Choose attribute group, and two attributes to connect – then click connect. That’s all.
You don’t have to edit attributes in any products. This plugin do it for you.