PorezPorezych [1] filed a deletion request for multimc5-offline [2]:

This package contains MultiMC with support for pirating Minecraft. Pirating Minecraft is illegal under the Minecraft EULA. Additionally, this package is named MultiMC while containing patches that prohibit it from being called MultiMC under the MultiMC license.

[1] https://aur.archlinux.org/account/PorezPorezych/ [2] https://aur.archlinux.org/pkgbase/multimc5-offline/