edhseer Commander synergy, explained
Sorcery
Mana cost: {3}{B}{B}
Exile all cards from target player's graveyard other than basic land cards. For each card exiled this way, search that player's library for all cards with the same name as that card and exile them. Then that player shuffles.
on-cast — hits a graveyard
on-cast — searches a library
on-cast —
on-cast —
Causes: exile a land, a land leaves a graveyard, search your library, exile a card, shuffle a library.
Cares about: nothing.
a library is searched — 982 cards in the game can cause this (Haunting Echoes is one).
When a permanent searches a library thanks to Haunting Echoes:
anything is exiled — 2,497 cards in the game can cause this (Haunting Echoes is one).
a sorcery is cast — 3,720 cards in the game can cause this (Haunting Echoes is one).
When Haunting Echoes is cast:
424 other cards care about it too. These are the ones with the most connections.
anything is cast — 31,128 cards in the game can cause this (Haunting Echoes is one).
When Haunting Echoes is cast:
5 other cards care about it too. These are the ones with the most connections.