Lastedge is actually not a spell but is a magical defense created and used by Klaus. It forms a web around its user and moving throughout the web are poisonous spike in the form of snails. It is a very effective defense capable of blocking any close combat attacks and if the enemy touches the spikes the poison can render them blind and weak. While it is powerful it isn't perfect, Everfight can heal the poison and Dante was able to pull it off Klaus barehanded.