Shadow of the Grave is oddly worded - how does one cycle a card without discarding it? It's part of the friggin' cost of cycling a card (i.e. any card you cycle falls under the clause "cards you discarded this turn" - therefor there's no need to specifically mention cycling on SotG).
maaaybe there is a super edge case where a replacement effect alters discarding into: put it into your graveyard instead