Vortex

Against most bosses the winning plan is to stack damage and buffs in one spot. Against Vortex that plan gets you stunned. Every skull knocks Vortex back and hits everything near it with a long stun, while the sped-up bloons behind it rush past your frozen kill zone. The answer is range and spread: hit Vortex from far away and keep a second line of defense for whatever slips through.

Why Vortex is dangerous

• Long tower stuns. A tier 1 skull stuns nearby towers for 16 seconds and a tier 5 skull for 27 seconds (18 and 30 on Elite). Stunned towers cannot attack, earn income, use or recharge abilities, or be sold.
• Fast bloons. Slipstream makes everything behind Vortex move at 2.5x speed until it catches up, and the event rules usually speed bloons up even more.
• Projectile deletion. The storm pulse wipes spikes, bananas and slow projectiles near it every few seconds.
• Storm shield. For 6 seconds after each skull, most projectiles bounce off.
• It is the fastest boss. It reaches deep into your track much sooner than Bloonarius or Lych.

Damage sources that work

• Infinite or long range. Sniper Monkeys, Monkey Aces, Heli Pilots, Dartling Gunners and Mortars can hit Vortex from outside the stun radius.
• Instant and fast attacks ignore the storm shield: Sniper bullets, Plasma Accelerator and Ray of Doom beams, Mortar shells, Ballistic Missiles and Heart of Thunder lightning.
• Sticky attacks such as Sticky Bomb keep damaging Vortex through the storm pulse.
• Bonus boss and MOAB damage, especially from Paragons, as long as they stay outside the stun radius.
• What does not work: stuns, slows and knockback on Vortex itself, percentage damage, and spike-based kill zones right next to it.

Best towers and setups

Tiers 1 and 2

• Elite Defender (Sniper Monkey, bottom path tier 5): map-wide damage that is never in stun range and ignores the shield.
• Master Bomber (Ninja Monkey, bottom path tier 5) and M.A.D (Dartling Gunner) for heavy boss damage.
• First Strike Capability (Monkey Sub): big ability damage from anywhere.
• Triple Guns or Armor Piercing Darts Subs with Advanced Intel (2-0-3 or 2-0-4): they shoot through the range of your other towers, so they can sit far away.
• Aircraft Carrier, Carrier Flagship, Monkey Aces and Heli Pilots: their aircraft attack all over the map. Keep the ship, runway or helipad away from the track, because Heli Pilots and Aces are only stunned if their pad or runway is inside the stun radius.

Tiers 3 to 5

• Paragons placed out of the stun radius, for example the Nautic Siege Core.
• Plasma Accelerator and Ray of Doom for shield-piercing beams.
• Apex Plasma Master can even stunlock Vortex near the entrance, because its bouncing projectiles keep hitting it, especially inside the shield.

Heroes that help

• Long-range heroes that are not stunned by staying out of range. Keep your hero away from the track where Vortex reaches its skulls.
• Benjamin for income, because Banana Farms near the track lose bananas to the storm pulse and stop producing while stunned.

Powers and Monkey Knowledge

• Power projectiles are not destroyed by the storm pulse, so Road Spikes, Glue Trap and MOAB Mine all stay useful for the fast bloons and blimps.
• Monkey Boost helps you break a skull quickly while your towers are not stunned.
• Range knowledge for your main tower type helps you stay outside the stun radius.

Tier-by-tier plan

1. Early rounds: expect more fast bloons than usual and a speed bonus from the event rules. Build a defense that covers the whole track.
2. Tier 1 (round 40): place your main damage at long range. Keep Banana Farms well away from the path.
3. Tier 2 (round 60): add a backup defense behind your main kill zone for sped-up bloons. Each skull stuns towers within 65 units for 19 seconds.
4. Tier 3 (round 80): move to Paragons and tier 5 towers, still out of range.
5. Tiers 4 and 5: stun radius grows to 75 and 80 units and lasts 24 to 27 seconds. Anything near the track where Vortex hits a skull will be out for a long time, so spread your damage along the path.

Normal vs Elite

• Normal has 3 skulls and storm pulses every 5 seconds.
• Elite has 7 skulls, so you face twice as many stuns, shields and knockbacks. Storm pulses come every 2.5 seconds and stuns last 18 to 30 seconds. Elite also moves faster, up to 19.2% of a Red Bloon at tier 5.

Counters to each ability

• Slipstream: keep a defense line behind your boss damage and protect every lane on multi-lane maps.
• Storm pulse: avoid spike and projectile kill zones right next to Vortex. Sticky Bomb, beams and hitscan attacks are unaffected.
• Skull stun: keep important towers more than 80 units from the track or use towers whose attacks come from far away.
• Storm shield: rely on instant attacks for the 6 seconds after each skull, or time abilities for when the shield drops.
• Knockback: Vortex walking back over the same stretch of track is a chance for your towers there, so place damage where it gets knocked back to.

Common mistakes

• Packing a buffed Alchemist and Village cluster next to the track. It deals great damage until the first skull stuns all of it.
• Placing long-range towers like Snipers, Dartlings, Aces and Helis right next to Vortex, wasting their range.
• Leaving Banana Farms near the path, where Vortex blows away bananas and stuns the farms.
• No backup for the fast bloons behind Vortex.

Frequently asked questions

How much health does Vortex have?

Normal Vortex has 20,000, 62,800, 294,000, 628,000 and about 2,512,000 health for tiers 1 to 5. Elite Vortex has 41,800, 251,000, 1,675,000, 6,700,000 and 33,500,000.

How long does Vortex stun towers?

From 16 seconds at tier 1 up to 27 seconds at tier 5 on Normal, and 18 to 30 seconds on Elite. The stun radius grows from 60 to 80 units.

What is the best tower against Vortex?

Elite Defender is the classic pick because it hits from anywhere and ignores the storm shield. Master Bomber, M.A.D, First Strike Capability and Plasma Accelerator are also strong.

Can Vortex stun Paragons?

Yes. Paragons inside the shockwave radius are stunned like any other tower, so place them away from the track.

Why are bloons so fast in Vortex events?

Vortex gives all normal bloons 2.5x speed until they reach it, and the event rules usually add extra bloon speed on top.

What attacks go through Vortex's shield?

Instant or very fast attacks such as Sniper Monkey bullets, Plasma Accelerator beams, Mortar shells, Ballistic Missiles and Heart of Thunder lightning.