The Wretched

At end of combat, gain control of all creatures blocking this creature for as long as you control this creature.

Masters Edition III

At end of combat, gain control of all creatures blocking The Wretched as long as you control The Wretched.

Once I had the strength but no wisdom; now I have the wisdom but no strength.
—Persian proverb

Fifth Edition

Chronicles Foreign Black Border

Chronicles

At end of combat, gain control of all creatures blocking The Wretched. Lose control of these creatures if The Wretched leaves play or if you lose control of The Wretched.

Legends

At the end of combat take control of all creatures that blocked The Wretched. The Wretched does not tap or untap these creatures. You lose control of these creatures if The Wretched leaves play or if you lose control of The Wretched.

Any blocking creatures that regenerated during combat will have been removed from combat. Since such creatures are no longer in combat, they cannot be blocking The Wretched, which means you won’t be able to gain control of them.

If The Wretched itself regenerated during combat, then it will have been removed from combat. Since it is no longer in combat, there cannot be any creatures blocking it, which means you won’t be able to gain control of any creatures.

The ability grants you control of all creatures that are blocking it as the ability resolves. This will include any creatures that were put onto the battlefield blocking it.

If The Wretched leaves the battlefield, you no longer control it, so the duration of its control-change effect ends.

If you lose control of The Wretched before its ability resolves, you won’t gain control of the creatures blocking it at all.

Once the ability resolves, it doesn’t care whether the permanents you gained control of remain creatures, only that they remain on the battlefield.

The Wretched’s ability triggers only if it’s still on the battlefield when the end of combat step begins (after the combat damage step). For example, if it’s blocked by a 7/7 creature and is destroyed, its ability won’t trigger at all.