When does a Chain level up?

Solution 1:

When killing the same type of enemies, the level of the chain increases at the influence of picking up the loot

Increasing the Chain Level is partially random, but is influenced by the player picking up the loot items enemies drop.

The "experience counter" towards leveling up your chain is a hidden counter, which decreases every time you pick up an item

Every time the player picks up loot the hidden counter towards the next level up will go down by 1 (Lv 0), 2 (Lv 1), or 3 (Lv 2)

This means that every time you pick up the loot, the number of enemies it takes increases.

You can still pick up the loot that is dropped, but it will take longer to level up the chain

Even if the player picks up all loot the chain will still level up eventually, because the game forces a chain level up at certain stages

If you ignore the loot that is dropped, the chain will increase fairly quickly

If the player does not pick up loot one can always level up the chain between 6 to 10 kills, reaching the highest Chain Level in 18 to 30 kills.

On occasion, the chain counter will begin to flash. If this is flashing, you are able to pick up the loot without the penalty of increasing the number of monsters required to level up

From time to time the player may notice the chain number flashing. This happens 5% of the time, and indicates the player can now pick up loot without penalty