For those of you who don't know what Overdrives are, they mainly replace the power-up moves (e.g.: Ragna's Blood Kain, or Bang's Fu Rin Ka Zan). The gold Burst (Offensive Burst) has been replaced with this, meaning, yes, you will lose your burst. Also included is Guard Crush that takes 25% of your Heat, it can be Barrier guarded though.
List of Overdrives: Ragna: Blood Kain Idea
Jin: Frost End - All attacks involving Yukinaesa freeze on contact
Noel: Chain Quasar - Increases speed of drive moves
Rachel: Erufreed(?) - Increases speed of Slypheed gauge recovery
Tao: Almost Becoming Two!
Tager: Voltic Field - Forces magnetism on opponent
Litchi: Daisharin - Manual control of staff using joystick + D button
Arakune: Crimson Deeps - Extends curse duration
Carl: Syncro High Speed - Improves Nirvana's strength
Hakumen: Kishin - Increases magatama rate, can cancel D counters into special moves, but cannot perform guard crushes
Tsubaki: Second Install - Install gauge automatically charges over time
Hazama: Jormungand - Strengthens drive attacks, gets life steal ring from Unlimited ver.
Makoto: G.Impact - All Impact moves are done at Level 3
Valkenhayn: Andross(?) Wolf - Quickly accelerates wolf gauge recovery
Platinum: Magical Heart Catch - Removes limit on weapon usage summoned with Drive
Relius: Maximum Dance - Increases Ignis gauge recovery
Amane: Cyclone - All drive attacks are at highest level
Bullet: Heat the Beat - Always in Heat Up state
Azrael: Mind Corroseo(?) - All attacks act like they hit weak points(?)