User blog comment:B214/Volume 23 discussion blog/@comment-26293136-20170806170338/@comment-10330822-20170806181401

Some are, some aren't. For example, the members of Sona's peerage had Artifical Sacred Gears put into them. While Azazel's artifical SG, Down Fall Dragon Spear, was just held by him. To my knowledge, I believe Euclid's Boosted Gear Replica was also just something he wore, it wasn't "inside" of him.