These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.04 s (backtrack: 0/20).

[ebuild  N     ] acct-group/greetd-0-r3::gentoo  0 KiB
[ebuild  N     ] acct-user/greetd-0-r4::gentoo  0 KiB
[ebuild  N     ] gui-libs/greetd-0.10.3-r1::gentoo  USE="-debug (-selinux)" 26198 KiB
[ebuild  N     ] gui-apps/tuigreet-0.9.1-r2::gentoo  USE="-debug" 8774 KiB

Total: 4 packages (4 new), Size of downloads: 34971 KiB