First things first: focus only buy Odin Diamonds on your main quests. While it might seem tempting to wander off and grind random mobs for a quick level-up, resist the urge! Main quests are your golden path, unlocking core systems that are crucial for your gameplay, including codecs, rune slots, town quests, and weekly dungeons. Grinding mobs before reaching level 50 is likely just a waste of your valuable time. Stick to your main quests to ensure you're making meaningful progress.