MTGNexus

Kediss, Emberclaw Familiar
Slicer, Hired Muscle // Slicer, High-Speed Antagonist

If I deal combat damage with Slicer and have Kediss onboard, will the damage Kediss deals be considered commander damage?

Commander damage only counts combat damage. Kediss deals damage via a triggered ability, which is noncombat damage. So no, it won't count as commander damage.

Great thanks