Please avoid using this guide until you've reached Act ... the main story quest 'A Reckoning in Blood' in Act 2. You can find the grave on a cliff overlooking the sea East of Yarikawa.

The latter is used to upgrade elite summons, but for early game spirits, you can use Grave Glovewort. So, where can you find these elusive plants? If you are struggling to find these upgrade ...

By sneaking up to the blue garage, you can use a Rewire Kit to hack the turret ... walk over to the mausoleum near the tombstone to find a Grave Lock inside.