The Lake of Lament is similar to the Future Pool, but much larger and used by the Ten Terrors. Sculpin went to the lake and asked it to show him The Master. However, what appeared to him instead was Koragg, with the voice of Leanbow.
Leanbow told the Terror that the Master would never rise up, that he would not allow it. As the projection of Leanbow went to strike Scuplin, the fallen warrior disappeared.
Scuplin later used the Lake again, but this time to force Leanbow out of hiding. By showing him the battle of Megahorn & Black Lance against the Rangers, he knew Leanbow would leave to aid the Rangers.