Slow homing wisp tears
What changes
Prayer Card still grants an eternal heart on use. Its wisps fire slower-moving homing tears from the inner ring.
How to approach the setup
Keep Prayer Card combined with the book. Consider using a charge near the floor exit when you want to carry an eternal heart safely into the next floor.
A practical suggestion for this pair. Check the rest of your inventory and the room before relying on it.
The caution to remember
The modified tears belong to the wisps. This does not give Isaac the Sacred Heart collectible, and the wisps do not protect the eternal heart from health damage.
What this teaches about a run
One activation can help both the current fight and future health. Separate the temporary combat helpers from the heart you are trying to preserve.
Other reviewed pairings
Book of Virtues + Yum HeartUsing Yum Heart with Book of Virtues creates heart-shaped wisps alongside its healing.Book of Virtues + Shoop da Whoop!Shoop da Whoop! creates wisps that fire thin lasers when you use the active, instead of shooting ordinary tears.Book of Virtues + Unicorn StumpUnicorn Stump creates rainbow wisps that can deal contact damage while Isaac is invulnerable.