Shallow Grave is not supposed to protect against spells which instantly kill targets.

Examples:

* If you are a Wraith Ghost due to WK's aghs upgrade, Shallow Grave doesn't prevent you from dying after the 7 seconds of Wraith Delay.
* Bloodstone can still be used to suicide during Shallow Grave.
* When Phoenix is graved, casts Supernova and the egg gets destroyed, Shallow Grave doesn't prevent his death
* Grave used to not prevent the old Suicide Squad Attack

So it's clear it's not supposed to prevent insta-killing effects. But it does prevent these:

1. Primal Split
2. Stone Gaze (vs illus)
3. All 3 hexes (vs illus)
4. Mana Drain (vs illus)
5. Life Drain (vs illus)
6. Glimpse (vs illus)
7. Dagon (vs illus)

Primal Split is the worst one. Shallow Grave does not prevent your death, but does completly bug it out. If you are graved, then enter Split Form, and then have your spirits killed before the grave expires, you die. But your death is delayed until Primal Split ends, and the death is not counted towards anything. Your death count doesn't increase, the enemy gets absolutely no credits, and not even the scoreboard counts it.

Stone Gaze cannot remove illusions who face Medusa for 2 seconds. It instead puts the illusions at 1 health and petrifies them.

Glimpse and the 3 hexes (Lion, Shaman and Sheepstick) put the graved illusion to 1 health and do nothing else. The illu does not get moved by Glimpse, and does not get hexed by the hexes. Only its hp is set to 1 and it survives.

Mana Drain and Life Drain set the illu's health to 1 on each of the drain ticks. They do not drain mana/life at all, so you basically channel to keep the illu at 1 hp.

Dagon is supposed to instakill illus as well, but like the other mentioned spells, it just puts them to 1 hp.

Current behavior: Shallow Grave prevents the instakill effects of Primal Split, Stone Gaze, Hex, Hex, Hex, Mana Drain, Life Drain, Glimpse and Dagon.

Expected behavior: The named instakill effects should ignore Shallow Grave.