This building is unlocked at Town Hall 5. This is where you brew Spells, a main thing in the game. You are able to upgrade this to level 5 at the moment. These spells will determine a lose or a win depending on what you use.
Use this spell, and why?
You use it because it zaps down a strike of lightning at buildings and/or clan castle troops. It can also be leveled up in the Laboratory. This will be useful in many situations.
What enemy troops do I use it on?
Groups of Archers. They deal most damage to your troops
Dragons that ruin your GoWiPe or any other attacks. These dragons will ruin your raid and wipe out your entire army if you don't use it on them!
Wizards. They deal splash damage and hit really hard. Lava Hounds. They can survive 5 max lightning spells and still go
Hog Riders. They die too easily and it is a waste to lightning spell them.
Wall Breakers. Just why would you spell them? Well if a full CC wall breakers could deal minimum damage to your army single targetly P.E.K.K.As. They only hit single target and you can take it out with mass dragons.
What buildings to use it on, and what to not?
Low health. If you see a building with low health, drop one down to get some extra percentage.
Mortars. They have low health (about 300). Drop one (or 2) to take it out.
Air Defenses. They have really low health. If you are going for an Air Assault, zap one down to take it out and clear up some
Town Hall. They have really high health and cannot be taken down by a few spells.
Archer Towers. They have high hitpoints but unless you want a few damage out to weaken it then you may zap them. Traps. The spell does nothing against traps what-so-ever. It doesn't disarm it or set it off.
What Troops should I use this on?
Giants. They need health to take on the rest of the base.
Wizards. They have low health but high damage. Keep voldemort alive!
Balloons. They are good for attacking but if you need to take out Clan Castle Troops, then let it drop!
Golems. They are your main tank. Keep them alive for a better distraction!
Don't use it on:
Minions. They die too quickly from even a level 1 Air Defense.
P.E.K.K.As. Only heal them when it is an emergency or if they are the only troops left. They hit too slow.
Anything else you can use it on because it is a normal chance they won't get taken out by this IMO.
What Troops to use it on, and what not?
Golems. They have a hard time breaking through Walls, and it gives them 100% more damage to take Buildings down.
Heroes. Sometimes, your Heroes don't have the special ability to rage up. The Rage Spell solves that! The Heroes can really help you in battle.
Balloons. They deal massive damage if combined with a Rage Spell.
Anything else is fine. It actually works well with most Troops.
What level Walls to use this on?
Actually, it works on any level wall and is always useful. Sometimes you can even jump your way to the Town Hall.
You unlock this at Town Hall level 10. You can use this in many situations.
What to use this on, and what not?
Inferno Towers. It deals massive damage to your Troops and you can die fast. X-Bows. Hurts Troops fast and kills Tier 1 Troops really fast. DONT USE IT ON: Cannons. Waste of a spell, they can easily be taken out Archer Towers. Another waste of a spell. Only use it if one of the above is near it.
I hope you found some good information here and i hope you have a good day.