I have to go with Illusionist. It can be absolutely devastating when played well. Who cares how many hit points damage the abjurer can take when you can't even hit the Illusionist? As for high level play, the Illusionist can take Silent Image and make anything real. You need a wall for the entire party to take cover behind? You've got that. Plus, Illusionists have flair. They might have the most flair of any subclass. Abjurers are kinda dull. Sure, they can get in the front lines, but once the novelty of that wears off, then what do you got?
After Illusionists, I'd pick Conjurer. Again, lot's of flair and if you play them right they can be devastating.
I can get behind this. I mostly create my high level characters for one-vs-one duels where the abjurer can really shine, but for a campaign yeah, you might want more. However, an abjurer could still destroy the illusionist in a fight - the illusionist can't do anything to the abjurer either, thanks to Invulnerability and the heightened power of an abjurer's Counterspell renders the illusionists illusions unusable.
You can't Counterspell what you can't see.
As for Invulnerability, there's a lot of things that can be done to you even when you have that up. Imprisonment is an example.
Illusionist. Because you'll probably have somebody else in your party for damage output, (wizards aren't usually the class for that - I would go with something more like a barbarian for damage) it's more helpful to help them than to do damage yourself. As an illusionist, you bamboozle your opponents and make it easier for the rest of the party to do their jobs (you will make your barbarian very happy for making it easier to hit things). All traditions are the shiny new object when your first see them, but some of them dull at higher levels. With illusion, though, you can create (almost) anything with your spells (as long as the DM doesn't say no). This tradition is as big and fun as your imagination.
To actually answer your question about making an offensive mage, you'd have to be an evoker. With spells like the classic fireball, lightning bolt, and (my favorite damage spell) meteor swarm, evoker does serious damage.
The typical wizard has an unfortunately low armor class and not much health, so it's better to support your party and let your barbarian do the damage.
Enchantment is the best out of combat though. When you get to twin your enchantments, that's a huge boon - particularly for lower levels where you don't have Mass Suggestion. The Alter Memories feature was built for stealth missions too. The biggest trouble with Enchantment is when you come across creatures with charm immunity.
Twinning Power Word spells is excellent too and Hypnotic Gaze is great for battlefield control.
I’d say necromancy, damage-wise I believe it’s the best if you know what your doing and since Necromancy is already morally dubious acquiring 3 pearls of power should be easy enough so at level 6 you can have 24 skeletons and equip them each with great swords so you can deal 48d6 damage with an extra 4d4 + 4 force damage from a second level of magic missile at a total of i believe 306 maximum damage on your turn and at level 8 it skyrockets to 402 maximum damage in just 2 levels
You can't Counterspell what you can't see.
As for Invulnerability, there's a lot of things that can be done to you even when you have that up. Imprisonment is an example.
I chose Conjuration because you can summon your own creatures to fight that, if you have an enchantment wizard/bard on the team plus you, you win.
Illusionist. Because you'll probably have somebody else in your party for damage output, (wizards aren't usually the class for that - I would go with something more like a barbarian for damage) it's more helpful to help them than to do damage yourself. As an illusionist, you bamboozle your opponents and make it easier for the rest of the party to do their jobs (you will make your barbarian very happy for making it easier to hit things). All traditions are the shiny new object when your first see them, but some of them dull at higher levels. With illusion, though, you can create (almost) anything with your spells (as long as the DM doesn't say no). This tradition is as big and fun as your imagination.
To actually answer your question about making an offensive mage, you'd have to be an evoker. With spells like the classic fireball, lightning bolt, and (my favorite damage spell) meteor swarm, evoker does serious damage.
The typical wizard has an unfortunately low armor class and not much health, so it's better to support your party and let your barbarian do the damage.
This thread is invalid because you have not included the hands down best subclass. The chronurgist is mechanically the most powerful of all.
“I will take responsibility for what I have done. [...] If must fall, I will rise each time a better man.” ― Brandon Sanderson, Oathbringer.
Enchantment is the best out of combat though. When you get to twin your enchantments, that's a huge boon - particularly for lower levels where you don't have Mass Suggestion. The Alter Memories feature was built for stealth missions too. The biggest trouble with Enchantment is when you come across creatures with charm immunity.
Twinning Power Word spells is excellent too and Hypnotic Gaze is great for battlefield control.
Chilling kinda vibe.
Few things are more powerful than messing with action economy, and that is what the conjuration wizard does through its sunmons
Is the chronurgist meant for regular play?
Though with the new supplement scribe easily beats all of these and comes in a close second to chronurgist.
I’d say necromancy, damage-wise I believe it’s the best if you know what your doing and since Necromancy is already morally dubious acquiring 3 pearls of power should be easy enough so at level 6 you can have 24 skeletons and equip them each with great swords so you can deal 48d6 damage with an extra 4d4 + 4 force damage from a second level of magic missile at a total of i believe 306 maximum damage on your turn and at level 8 it skyrockets to 402 maximum damage in just 2 levels
You forgot about blade singer.