Kills by other means, even if triggered by gems, will disqualify you. To do this easily, reach a reasonable wizard level and have enough mana to build a few traps. Start the F1 level without traits then build a few traps along the monsters' path. Use only orange and a few purple gems. The lowest gem level should be enough. Some monsters may get banished once or twice, however it should not destroy the orb because the monsters do not consume too much mana. Note: By using only poison gems in the traps on the level F1 level, you easily earn "Green Vial".