It was a little hard to follow at first with the 3 levels and using the right element and right level in the right order, and understanding how the tree branches in the top right and what seal effects you'll get.
Even tutorial videos from big name publications didn't seem to fully understand it.
I have it down pat now.
The other level to it is if you hit someone with say a 3rd level combo and it's like wind element. Then the enemy is going to have a wind element resistance bubble. But if you use you're chain attack you will se which elemental bubbles the enemy has and if you specifically chain attack against that element you can burst the elemental protection on the enemy and do crazy damage to them. So you can engineer combos to land on different elements for maximum damage then potentially burst all the bubbles with a chain attack after.
I just laid 119,000 chain attack with 3 elemental bursts down on a boss, (won't spoil don't know where everyone is in the game) and it felt so good