qmk_firmware/keyboards/bastardkb/scylla/keymaps/cykedev/rules.mk

MOUSEKEY_ENABLE     = no      # Mouse keys
NKRO_ENABLE         = yes     # USB Nkey Rollover
RGB_MATRIX_ENABLE   = no      # Enable keyboard RGB matrix
KEY_OVERRIDE_ENABLE = yes     # Enable Key Overrides, see https://docs.qmk.fm/#/feature_key_overrides