Note: the most important change here is that FreeMinecraftModels can now be used as a drop-in replacement for ModelEngine, meaning the software used to show custom models to players is now free!
I am the author of FreeMinecraftModels, by the way.

EliteMobs 8.7.0 changelog:
- [New] Added FreeMinecraftModels as a drop-in replacement for ModelEngine! ModelEngine R3 will still work for now, but support will be dropped in the future
- [New] Arenas are now able to spawn Mythic Mobs as wave bosses!
- [New] Added the elitemobs-explosion-block-damage flag, which when denied makes fireballs still do damage but not damage the terrain
- [Fix/Revert] Fixed issue where players couldn't pick up elite currency. This reverts a previous compatibility fix for plugins that change item pickup behavior
- [Fix] Fireballs now do damage correctly when appropriate
- [Fix] Custom boss spawn with level command will now work correctly for bosses with a dynamic level
- [Tweak] Remove command stops removing if you relog
- [Tweak] Thoroughly optimized the PlasmaBlaster power based on feedback
- ...and more