Activate Ludevic by paying {1}{U}{U}{B}{B} and exiling Mirror-Mad Phantasm from your graveyard, transforming Ludevic into a copy of Mirror-Mad Phantasm with the name Olag, Ludevic's Hubris instead.
Activate Olag by paying {1}{U}, shuffling Olag into your library and putting your library into your graveyard due to it not containing a card named Mirror-Mad Phantasm in it.

Infinite self-mill

Ludevic, Necrogenius // Olag, Ludevic's Hubris

Mirror-Mad Phantasm

Whenever your life total would be reduced to zero or less, Olag instead sets your life total to three and transforms into Ludevic, but remains a copy of Enduring Angel.
The next time your life total would be reduced to zero or less, Ludevic instead sets your life total to three and transforms into Olag, but remains a copy of Enduring Angel.
Repeat.

Combos with "Ludevic, Necrogenius // Olag, Ludevic's Hubris"