Dualcaster Mage + Thunderous Debut + Mortuary + Phyrexian Altar

Dualcaster Mage

Thunderous Debut

Mortuary

Phyrexian Altar

How it works

1. Cast Thunderous Debut by paying 6 and sacrificing an artifact, enchantment or token.
2. Holding priority, cast Dualcaster Mage by paying 1.
3. When Dualcaster Mage enters the battlefield, it triggers, copying Thunderous Debut.
4. Activate Phyrexian Altar by sacrificing Dualcaster Mage, adding one mana of any color.
5. When Dualcaster Mage dies, Mortuary triggers, putting Dualcaster Mage on top of your library from your graveyard.
6. Resolve the copy of Thunderous Debut, causing you to look at the top twenty cards of your library and put Dualcaster Mage and up to one other creature card onto the battlefield.
7. Repeat from step 3.

This intricate loop starts by casting Thunderous Debut with its bargain cost paid, setting up the top of your library while you hold priority to slide Dualcaster Mage onto the stack with flash. When Dualcaster Mage enters the battlefield, its triggered ability targets the original Thunderous Debut to make a copy, which will soon resolve to pull Dualcaster Mage and another creature straight from your library onto the battlefield. Meanwhile, Phyrexian Altar provides the sacrifice outlet needed to generate mana of any color while sending Dualcaster Mage to the graveyard, instantly triggering Mortuary to seamlessly place Dualcaster Mage right back on top of your library so the whole sequence can repeat indefinitely.