Cast the non-card copy of the spell in exile by paying its mana cost, unpreparing
Emeritus of Woe // Demonic Tutor.
When you cast that spell,
Spellweaver Helix's last ability triggers, allowing you to cast a copy of the Extra Turn Sorcery without paying its mana cost and take an extra turn after this one.
Resolve the spell from step 1.
Activate
Lilysplash Mentor by paying mana, flickering
Emeritus of Woe // Demonic Tutor, which enters prepared.
Repeat each turn.
Results
Infinite turns.
Metadata
This combo produces a lock.
In 0 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Ruthless (Bracket 4+).