Azure Guardian Armor + Azure Guardian Helm + Aegis - 20k ce(18k ce if you provide recipes and mats)
or
Mighty Cobalt Helm + Mighty Cobalt Armor + Mighty Defender - 7.8k ce or 2.9k ce each

It's Lv10 Mighty Cobalt set now, so you can choose to have 5* or 4*.
Since 4* stuff is really hard to level up, so i suggest you to choose 5* one.

IGN: Lightee