parasol said:
You're still losing a valuable index, if the link is dead you've lost the whole site.
http://web.archive.org/web/*/lawpula.blog87.fc2.com/*
"60 URLs have been captured for this URL prefix."http://web.archive.org/web/*/lawpula.blog.fc2.com/*
"No URL has been captured for this URL prefix."
You already have to deal with this because many fc2.com blogs already redirect to another site. http://android217.blog126.fc2.com (android217) now redirects to http://android217.blog126.fc2blog.us and http://moritakuya.blog.fc2.com (Yashiro Yuuya) now redirects to http://moritakuya.blog.2nt.com. The blog number alone isn't enough to find it in the Wayback Machine, it's always possible the blog moved to a totally different domain.
Another reason: duplicate artists. I just noticed that Mori Takuya is a duplicate of Yashiro Yuuya. This wasn't noticed before because Mori Takuya had http://moritakuya.blog36.fc2.com/ in their artist entry, but Yashiro Yuuya had http://moritakuya.blog.fc2.com.