Cactus Unlock Build - Aethena

To unlock the cactus, you need to kill 100 cactus with thorns. Athena comes with thorns and receives 2 per level up so she is the obvious choice. Reduce your weapons to 2, but you really only want Aegis running to prevent killing the cacti with anything other than thorns. You want to be a tank and just take the damage and only kill with thorns. Disable all items that will damage enemies. Survival only. This will be a lot of tries and cactus spawns aren't guaranteed either.