Okay, I use the sacrifice relic with my Ritualist and I noticed that the granted skill is shown as “Proc buff” on Grimtools? Sacrifice is a skill that you need to activate yourself so should it not be a “Temporary Buff”?
Do not get me wrong I am just curious as to why Grimtools shows it as a Proc Buff, I am not questioning the usefulness of the Sacrifice granted skill. 
It’s not shown as a proc buff, but a temporary buff.
That is not the Grimtools page I was referring to, I did not see it on the item page, but on the Grimtools calculator page.
https://www.grimtools.com/calc/L2JaBbEN
If you check the Proc Buff Icon you will see that it shows Sacrifice. It is good to know it is indeed a Temporary Buff, but that is not what the Proc Buff icon shows for me, hence my small curious question.
You should report that in the GrimTools thread. This is most likely an oversight.
PS: When you’re working with stuff like 3rd party tools, mods, etc., usually the mistake happens on their side and you should report to them to fix it.
Thank you BadWolf91, just did.