Meren Hag Deck Upgrade Recommendations?

[tawdry harness]

https://scryfall.com/card/rvr/218/savra-queen-of-the-golgari

Savra, Queen of the Golgari <:mana2:292901509060886528><:manab:292901508872273920><:manag:292901508654301185>

Legendary Creature — Elf Shaman
Whenever you sacrifice a black creature, you may pay 2 life. If you do, each other player sacrifices a creature of their choice.
Whenever you sacrifice a green creature, you may gain 2 life.
"Nature's most raw beauty is the circle: perfect in its continuance, with no break between death and life."
2/2

https://scryfall.com/card/2xm/209/mazirek-kraul-death-priest

Mazirek, Kraul Death Priest <:mana3:292901508771610624><:manab:292901508872273920><:manag:292901508654301185>

Legendary Creature — Insect Shaman
Flying
Whenever a player sacrifices another permanent, put a +1/+1 counter on each creature you control.
The clicks and buzz of the undercity proclaim him the incarnation of decay.
2/2

https://scryfall.com/card/khm/112/tergrid-god-of-fright-tergrids-lantern

Tergrid, God of Fright <:mana3:292901508771610624><:manab:292901508872273920><:manab:292901508872273920>

Legendary Creature — God
Menace
Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control.
Fear is her one true companion.
4/5

Tergrid's Lantern
Legendary Artifact
: Target player loses 3 life unless they sacrifice a nonland permanent of their choice or discard a card.
: Untap Tergrid's Lantern.
When Tergrid was a child, her shadow tried to kill her. Only her lantern keeps it at bay.