Soularia

This mod adds items to catch mob's soul, it needs Croparia to work. More customization with Croparia+

With their soul stuck in a jar, you can easily move any mobs or keep them as a decoration !

You can take a look at Patchouli (guide book for version 1.2+).

Soul Dagger

Recreate the tier 1 ritual structure (check screenshot of Croparia)

Replace the IRON BLOCK by ELEMENTAL STONE, and then drop a GOLDEN SWORD the ritual stand

Soul in a jar
With an empty JAR in your off-hand, kill any mob with the SOUL DAGGER. A soul in a jar will drop on the ground. Use it while sneaking to summon the mob.