Elder Puzzler is a pretty strong card with 6/7 and a 8G cost. Its ability works kinda as an opposide to Orange Laser, whereas Orange Laser deals damage to monsters that didn't attack, Elder Puzzler deals 2 DMG to a random enemy monster if it didn't attack. This includes the turn you summon it on, unlike Orange Laser.
This can be useful if you want to keep this monster alive while still damaging the enemy. For example, if there's only 1 enemy monster with 2 HP on the board, you can choose not to attack with this card so that monster will die and Elder Puzzler takes no damage.
This card works well in justice/control decks as it can do damage without taking damage itself.
As its ability requires it to not attack, the enemy can use Orange Laser to either force the enemy to attack with it or make it take 3 damage.