Makes powerful balls of lightning that shoot additional lightning bolts.
Ball Lightning is the 4th upgrade of the 1st path for the Druid. It adds an additional attack for the Druid, allowing it to shoot balls of lightning. These projectiles are slow-moving electric balls that create stronger lightning bolts (statistically stronger Heart of Thunder lightning bolts) when approaching bloons. Each lightning ball is shot every 6 seconds and the lightning from Ball Lightning spawns every 0.35 seconds dealing 2 damage to up to 30 bloons per lightning. Lightning balls have roughly ~25 range for spawning lightning bolts.
The Ball Lightning allows the Druid to launch a new type of slow-moving projectile alongside previous spells from upgrades Heart of Thunder, Druid of the Storm, and typical Druid thorns.
The projectile itself fires off Lightning Bolt attacks from itself, attacking bloons close to itself at a quick pace. If no bloons are present, it will not release these arcs of lightning. The slow movement, instead of hampering potency, is meant to help maximize the lightning strikes in this case, letting the ball attack multiple times to the same bloons.
Ball Lightning is usually used in combination with Poplust Druid strategies to help with bloon rounds. However, do note that in many cases, Poplusts themselves already defeat these rounds, especially with pierce buff/Wall of Trees support from Obyn Greenfoot, so it may be better to buy a cheaper variant of Druid, or to simply save the money for your other upgrades.
The slow attack speed of the ball lightning attack means that it can easily miss the large groups of bloons it is meant to target. Poplust boosting the Ball Lightning Druid helps with this by increasing the fire rate of the Ball Lightning attack.
Given the nature of the projectile benefiting from being in the range of bloons for a long period of time, using a Ball Lightning Druid similarly to a Juggernaut or Spike-o-pult would be ideal, allowing it to pass down the path and shock as many bloons as many times as possible before disappearing or going off the screen.
One notable aspect for Ball Lightning can also be unlocked with Monkey Knowledge Point called "Cold Front", allowing the ball to freeze bloons it attacks. Because this freeze is fairly weak, it usually only adds a small bonus to the actual power of the Ball Lightning.
Price decreased to balance out the damage.
Ball Lightning price decreased ($6,000 → $5,500).
Druid's top path Storm & Ball Lightning upgrades needed a value boost versus other options versus other paths of other tower choices, so these have been given a small price buff for now.
~ Ninja Kiwi
Ball Lightning price decreased again ($5500 → $5100).
As a 'druid buffing' hero, Obyn has in actuality been a bottom path druid buffing hero, so we've tweaked a couple extra levels to give more path specific bonuses to other druid paths that weren't benefiting as much from his wizened presence, regardless of whether your Obyn says "Fries" or "Clive". [...]
~ Ninja Kiwi, referring to Obyn
Ball Lightnings gain +20% projectile size and +1 MOAB-class damage if Obyn Level 9+ is on screen.