Beledros Witherbloom + Urza's Saga + Agatha's Soul Cauldron + Arwen, Weaver of Hope + Diamond Valley

Exhibition

How it works

Urza's Saga has two lore counters on it.
Lands you control except Urza's Saga can tap to produce at least .
Your life total is at least 11.
The number of artifacts you control plus Arwen's toughness is equal to or greater than 9.

Activate any number of lands except Urza's Saga by tapping them, adding at least .
Activate Urza's Saga's second ability by paying and tapping it, creating a 0/0 Construct artifact creature token that gets +1/+1 for each artifact you control, and that enters the battlefield with a number of +1/+1 counters equal to Arwen's toughness.
Activate the Construct using Beledros Witherbloom's ability by paying 10 life, untapping all lands you control.
Activate Diamond Valley by tapping it and sacrificing the Construct, causing you to gain at least 10 life.
Repeat.
If the number of artifacts you control plus Arwen's toughness is equal to or greater than 10, this combo nets infinite life, and if other lands you control can tap to produce at least , this combo nets infinite mana.
If you get infinite life and infinite mana, you may forego sacrificing the Constructs.

In which brackets is this combo allowed, per Spellbook's Exhibition tier?

1–2 · Exhibition & Core

Allowed in this bracket.

3 · Upgraded

Allowed in this bracket.

4–5 · Optimized & cEDH

All combos are allowed.