Teshar, Ancestor's Apostle | Aether Channeler | Sol Ring

(and one other card)

You have a historic permanent card in hand that can be cast using ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) .

({1} magic symbol) if the permanent requires five or more mana to cast available.

Activate
Sol Ring by tapping it, adding ({C} magic symbol) ({C} magic symbol) .
Activate
Ashnod's Altar by sacrificing
Aether Channeler, adding ({C} magic symbol) ({C} magic symbol) .
Cast the historic permanent from your hand by paying its mana cost.
Teshar triggers, returning
Aether Channeler from your graveyard to the battlefield.
When
Aether Channeler enters the battlefield, it triggers, returning
Sol Ring from the battlefield to your hand.
Activate
Ashnod's Altar by sacrificing
Aether Channeler, adding ({C} magic symbol) ({C} magic symbol) .
Cast
Sol Ring by paying ({1} magic symbol) .
Teshar triggers, returning
Aether Channeler from your graveyard to the battlefield.
When
Aether Channeler enters the battlefield, it triggers, returning the historic permanent cast in step 3 from the battlefield to your hand.
Activate
Ashnod's Altar by sacrificing
Aether Channeler, adding ({C} magic symbol) ({C} magic symbol) .
Repeat from step 3.

If the historic permanent can be cast for less than ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) , this combo nets infinite mana.