Sun Titan + Oblivion Ring + sacrifice outlet for Oblivion Ring = infinite sacrifices and ETBs
How it works:
- Have Sun Titan and a sacrifice outlet for Oblivion Ring on the battlefield
- Cast Oblivion Ring, exiling Sun Titan with its ETB ability
- Sacrifice Oblivion Ring, returning Sun Titan to the battlefield
- Return Oblivion Ring to the battlefield using Sun Titan's ETB ability
- Repeat