Mana Shield is one of the final upgrades in the Magic Monkey Knowledge Tree, along with Deadly Tranquility and the first Monkey Knowledge upgrade added, There Can Be Only One. When activated, a 'shield' will surround your life count, protecting you for 25 lives. At the start of every round, 5 lives will be regenerated to that amount, up to a max of 25. It requires you to already have 8 points into the skill tree before speccing into.
- Don't be afraid to let the shield tank some of the leaking bloons, with a maximum of 25 hit points, it can absorb a Lead Bloon entirely, with 2 lives remaining.
- This upgrade is very powerful early on and taking just 5 rounds to recharge means it is very useful for any weaker bloons that may slip by.
- This is very powerful upgrade for Impoppable, as you get +25 regenerating lives.
- If playing on Easy difficulty with maximum lives and the shield is at maximum health, it is possible to tank 2 Ceramic Bloons, surviving with 17 lives.