Felt like updating a Forensic Researcher Ertha Jo, Frontier Mentor infinite combo deck from a couple sets ago. It's become pretty weird. Maybe that's just the way I make decks.
The infinite engine comes from two Researchers untapping each other as a loop. Then Ertha Jo lets you copy the untap effect but target something else, like a land. So each activation untaps both a Researcher and a land, and you can loop the land untaps for infinite mana.
If you also have Unctus, Grand Metatect on the battlefield. Each Researcher tap triggers a card draw and discard. Looping Researchers means you can draw your whole deck, and find whatever ultimate cards you need. Unctus can also activate to add the draw/discard when tapped buff to them. Ertha Jo copies that effect too.
To protect the combo pieces, I'm trying Lost in the Maze and Skrelv, Defector Mite ability, (which Eartha Jo can also copy). To make Lost in the Maze a bit easier to use, I'm adding in some vehicles that can be crewed in response to incoming target effects. Subterranean Schooner and Unidentified Hovership specifically.
It's important to get more Researchers in the deck to get two out more consistently, so I'm giving Silent Hallcreeper a try. If a Researcher ends up in the graveyard, Agatha's Soul Cauldron can bubble up the untap ability for other creatures to use. The Schooner exploring spits out extra counters for your creatures to share in the Cauldron abilities.
I'm quite fond of Proft's Eidetic Memory fitting in, especially with Unctus going crazy with the draw/discard effects. And I like Ingenious Prodigy with Memory as a value draw engine and Teferi, Temporal Pilgrim as an Unctus-powered immediate one-sided super-sweeper that loves a good Memory.
For a finisher, I want to rely on Realmbreaker, the Invasion Tree once the infinite mana/untaps are online. A couple of Invasion of Arcavios
can open up extra finishers or utility spells from the sideboard, like a Doppelgang to copy the Invasion or This Town Ain't Big Enough to bounce the Invasion in a loop (or bounce the Unctus before you deck yourself, or just Step Between Worlds to restore your library). But you can shove in lots of different things that work with your own preferences.
This deck... seems to work...? It's not super smooth in the early turns, but it does get itself rolling like a turn earlier than what people expect. Awkward things like the vehicles and the tapped hexproof seem to blank some of the reactive staples in the meta where it's difficult enough for the opponent to navigate the extra +1/+1 counters attacking in on them. And you're getting a few extra cards as you go to keep your gas up.
