Soulseeker late in the game by using them to defend against the opponent. It can also be used in conjunction with the opponent's Orb of Unity if you're facing a green deck-- your skeletons will become as strong as their ants, if you have at least a few in play simultaneously. However, be careful against using too many corpses because without any in reserve, you can't play Giant Skeleton, Horrid Skeleton, Skeletal Warrior, etc. or heal Ghoul Lord, Savage Ghoul, etc.
Strong against: Orb of Unity, rush decks.
Weak against: Direct damage action cards such as Vampiric Bite.