Activate Phyrexian Altar by sacrificing Nyxborn Rollicker, adding .
When Nyxborn Rollicker dies, Mortuary and Ashiok's Reaper trigger.
Resolve the Mortuary trigger, putting Nyxborn Rollicker on top of your library from your graveyard.
Resolve the Ashiok's Render trigger, causing you to draw Nyxborn Rollicker from your library.
Cast Nyxborn Rollicker by paying .
Repeat.
This ingenious loop turns a tiny giant into an infinite engine by leveraging a clever mechanical overlap: Nyxborn Rollicker counts as an enchantment when it hits the graveyard while bestowed, allowing Ashiok's Reaper to draw you a card every time it dies. Meanwhile, Mortuary ensures the Rollicker never stays in the graveyard long, automatically sliding it back to the top of your library so you can redraw it. Phyrexian Altar acts as the financial engine of the operation, converting the creature into the exact red mana needed to recast the Rollicker and repeat the cycle indefinitely.