General Tips:
Spending the 200 crystals on the ship is not required, but will help you save time, and 200 crystals isn’t a lot, so it's a fair buy, but you can operate without it.
Dragon Flight - If the next floor has already been cleared by another player, at any point you can skip to the end of the floor, this skips all potential rewards from that floor, but may be necessary if you used all of your units.
Unit uses reset each day, and again at the very end of the event against the final boss, so use every unit you have. Purchasable refreshes also reset at these moments, but the rules for refreshes change in the final encounter. Spread out your refreshes, the cost increases after each refresh and rewards the same amount of points. (hammer rewards do however correspond to the cost of the refresh)
Gem packs also refresh each day if you’re looking to be a big spender or get high ranking.
Make sure your units are strong. Unit might will be referenced several times in this event and when you start it each day the unit mights lock in.
Ranking rewards give you the better currency that lets you buy L/D omni shards and Jing Ke/Pandora shards. Event participation rewards the other currency which can be traded for a good spread of training resources.
The shop has stages for purchasing items, the more you buy, the pricier it gets. The inventory (and the stages) refresh each month.
Hammers and potions will not disappear after the event is over, meaning you can use them in future events.
Floor Events:
Trade: These are almost always beneficial, and can give you a lot of valuable resources, always route to them.
Chest: Even if you buy all of the packs, if you travel enough, you will have many more chests than keys. If there’s something better on the other end path to that.
Hot Spring: These have a chance to be negative, but since it gives you a choice of which unit to impact, they are generally positive, so pick them up when possible.
You can back out of a negative hotspring event and take dragon flight when available to skip to the end of the floor so as not to get the might debuff, but you will skip further rewards on that floor as well.
Packs: Lets you spend money for more stuff. As a low spender, I avoid these, but that's up to your financial responsibility.
Monsters: These are global, if another player has cleared it, you will just skip the area, otherwise, you can commit a unit to fight, rewarding you with currency and points based on the strength of the unit, plus a bonus for the killing blow Don't Overcommit: committing a unit will reduce the monster’s life by the unit’s might, and rewards will be capped by the damage dealt, so don’t use units with tons of power for these events, save them for floor bosses.
Floor Boss: Also global. The same as monsters, but these have significantly higher life. The last hit bonus is greater, and afterwards there is a ruins event.
Bosses also have damage ranking rewards, which will give you extra points for being in the top 3 of damage dealers.
Ruins: After every boss, there is a 500 item, random bonus. This is first come first serve, but I haven’t seen all 500 rewards be claimed (in my battle zone at least). Rewards vary, and can even reward you with a red key if you're lucky.
Final Boss:
This shows up on the last day of the event, and replaces the floor boss of the last floor reached. This is the last encounter of the event, and as such undergoes different rules.
Units are refreshed for this event, and you can only use a potion to refresh them once per unit.
This does not happen when the boss appears but when you arrive at it, so you can progress through the floors you haven’t cleared without expending attempts at the final boss.
The boss has an incredible amount of HP, so much that last time it wasn’t defeated in my battle group.
The boss is only available for a limited time, missing out on it can mean missing out on a lot of rewards.
You still need to navigate to the boss with the same days unit uses, so be careful about spending them all beforehand.