this is a Post showing the Crafting limitations of Eternal Items, including Maps & Pets. all other Items don’t have these restrictions, except for Maps, which only Larimar & Diamond can be used, and Pets which only Calcite, Angelite, Quartz (don’t use this on any Item until you understand how it works, or you will regret it), Diamond, Larimar, Kyanite, Sapphire, Fluorite, & Topaz can be used (it costs 5 Crystals for each use on a Pet. so if it takes you 5 tries to change a Pets Element from Ice to Fire, it will cost you 25 Calcite).
an Eternal Vacuus Scipio would only be good for a Build using Proc Skills for DPS.
yes, any Crystal can be used on Legend Items.
they can be found on floors past 100 on any difficulty by killing Powerful enemies (Epic+ monsters, Orange, Red, & Purple). Nadroji Set & high Luck can increase the chance of having it drop when defeating Powerful enemies. you just need lots of Epic, Legend, & Mythic Enemies to defeat! 
