Continuum

Effects

(Added in Afterbirth †) (The Forgotten) The Forgotten: The skeleton form's charge attack can loop through walls.
A Lump of Coal: Tears will continually gain damage when passing through walls.
(Added in Repentance) (Azazel) Azazel/ (Tainted Azazel) Tainted Azazel/ Brimstone: The laser continues behind Isaac and back once again, potentially hitting enemies twice in one blast.
Mom's Knife: Causes Mom's Knife to appear on the opposite wall if thrown through one. It then returns through the wall to Isaac.
- Mom's Knife + Brimstone: The barrage of knives flies across the room until it hits the wall twice.
My Reflection: When shooting through a wall, tears speed up towards Isaac rather than returning through the original wall. With enough shot speed and range the tears can loop twice.
Tech X: Laser rings will go through walls, extra distance depending on shot speed.
- Tech X + Incubus: Incubus's laser rings cannot go through walls. This applies to (Lilith) Lilith too.
- (Added in Repentance):Tech X + Incubus: Laser rings travel through walls and continue on the other side of the room.
Tractor Beam: Causes the tears to loop right back in front of Isaac after they go offscreen.
(Added in Repentance) Revelation: The laser will loop around, potentially hitting enemies twice.
Any item that grants multiple shots like Loki's Horns and Mom's Eye are good items to take.

(Removed in Repentance) Brimstone: Overridden by Brimstone.
(Removed in Repentance) (Added in Afterbirth †) Compound Fracture/ The Parasite: Tears will only split when hitting obstacles or enemies but not walls.
- (Added in Repentance) Tears will split on contact with walls. Only one split will occur on contact with Walls and Objects.
Dr. Fetus: Bombs cannot go through walls, but are spectral.
Epic Fetus: Overridden by Epic Fetus, stat effects apply.
The Ludovico Technique: When the tear is moved offscreen, it loops back through the opposite wall.
Proptosis: Tears shrink while traveling through walls and often disappear before they can reappear on the other side.
Rubber Cement: Overrides Continuum.
(Added in Afterbirth †) Technology Zero: Tears will travel through walls; however, the electricity will not connect the tears while they are outside the room. Once tears have passed through walls, the electric arcs connect very erratically to other tears, limiting the efficiency of the combination.
Tiny Planet: Tears that travel through walls will travel until they reach Isaac and start orbiting him again.