Tremor is the only melee weapon ability that can lift an enemy into the air without changing your position. While this might seem rather trivial at first, it's actually a rather effective way of immobilizing a dangerous enemy and that use is doubled if it's an enemy such as the Ravager which can go into a rage and become hard to stun.
When you couple this with the fact that it's also quite capable of launching an entire group of enemies at a time, you can see how this ability truly shines. Find a long string of enemies, launch them into the air and then follow it up with any Aquila aerial combos to deal massive damage to large group and immobilize them in the air.
Want a really useful expert combo? Launch a group of enemies into the air with Tremor, hit them with the Aerial Buy In combo for Aquila and then change quickly to Osiris for a quick Double Up attack. Change back to Rebellion for a Roulette combo. Finally, switch to Eryx and charge a Stomp attack. You should have it fully charged just as the group of enemies is hitting the ground, allowing you to finish a large group of weaker enemies with a single combo. As an added bonus, this should give you a huge amount of style points.
