"You cannot be slowed to below base speed" - This has nothing to do with attack speed, cast speed, or movement speed, but rather with animation speed. I could only think of four things in the game that modified this: Chill, Freeze, Temporal Chains, and Acceleration Shrines. Therefore, players with this passive will be completely immune to the slowing effects of Chill, Freeze, or Temp Chains, unless they also have an Acceleration Shrine active, in which case these effects may still slow the player, but never below their normal animation speed that they would otherwise have if not under the effect of the shrine.
Movement Speed cannot be modified below base value - This works as most people have surmised. If your movement speed modifier would ever drop below 0% increased, it is instead exactly equal to 0% increased. So Tarred Ground can still affect you, but won't affect you as much as before if your move speed was less than 50% increased. The important distinction to make here is that neither Chill, Freeze, or Temp Chains modified your move speed, but rather modified your animation speed.
- As noted by PawnsAreOP, Cyclone gives 30% less movespeed, so if you
have less than 43% increased move speed normally, Unstoppable will
speed up your Cyclone!
- As noted by Totemizer, you will be immune to the immobilization
effect of Bear Trap. I tested and verified this one, too.
To Summarize: While using Unstoppable, the following occur:
- Cyclone: Still affects your move speed , but not below 0% move speed.
- Vaal Cyclone: Sadly you are still unable to move.
- Bear Trap: This appears not to affect you at all. Need more testing.
- Sea Witch Screech: Still affects you, but not below 0% move speed.
- Labyrinth Dart Trap: Still affects you, but not below 0% move speed.
- Labyrinth Spiked Floor: Still immobilizes you, probably because it
just acts as an obstacle.
- Chill: Does not affect you at all (unless you also have Accel.
- Freeze: Does not affect you at all (unless you also have Accel.
- Temporal Chains: Does not slow you at all (unless you also have
Accel. Shrine). However, it still increases the duration of effects
- Tarred ground: Still affects you, but not below 0% move speed.
- Suppressing fire: Still affects you since it only impacts attack and