Unreal Tournament 3

Here is the list of levels I chose to complete Chapter V. Where I have written [Select], I have been given a choice and this is the level I selected.

Important: If you select different levels to the ones I have listed below, your last level may also be different

Casual
(01) Omicron Dawn
(02) Sandstorm
(03) [Select] Sanctuary
(04) Fearless
(05) Necropolis
(06) Vertebrae
(07) FloodGate

Insane
(08) Sentinel
Card: None (You are not able to select a card).

I highly recommend doing this with friends on LIVE as it is seriously difficult and you will also gain the achievements for completing the Campaign in co-op. I played this with 2 others, we all grouped by the Rocket Launcher (atop the ramp covering the U-Damage). A player stood either side of the ramp, and the 3rd stood a little further back. You'll find Akasha always tries to head up the ramp hugging the wall, using the rocket launcher she becomes and easy and predictable target.

If you don't manage it at first, keep trying. We managed to complete it on our 3rd attempt and won 20 - 8.

Follow hatchywatchy's guide up till switching to Insane. Now this was found out the hard way when we had been boosting with 3 people and lost to Akasha at least 8 times. You can do this solution with 2 people as well.

Basically whoever is going for the achievement needs to be hosting the chapter (so if 2 people are doing this, each of you have to start chapter 5 as host and have the other person do the following). Have at least one other person join the match. When the match starts, have the non-host person drop. You will get -1 scored but you do get an insane bot in their place. (You may be able to get them to drop prior to the match start and not get a -1 and the bot but can't confirm).

I was able to get the win with 2 bots and myself on the first try. I have another friend that had me drop and was able to get the achievement with 1 bot and himself. 2 people against Akasha is next to impossible, so first try with 1 bot in a person's place may be the way to go.

--- Removed 2nd controller suggestion, does not work ---

This is definitely a hard achievement when it comes to simply beating up Akasha 1v1, but there are many things you can do to give yourself an edge over her while playing. I made a video demonstrating my strategy.

Key things to note in the gameplay:

Health vials [+5 health] (both spawns, 3 of them near rockets and 5 of them on the walkway under health packs)
Health packs [+25 health] (walkway near sniper)
Armour [+50 armour] (down flight of stairs from Bio Rifle)
Shield Belt [+100 armour] (Akasha will ALWAYS go for this when it is up)
U-Damage [+100% damage] (Akasha will ALWAYS go for this when it is up)
Rockets are main weapon, Bio rifle works well also.
If Akasha has a link gun, it'll slaughter you in seconds close range.
Good luck!

Campagne en ligne complétée
Pour obtenir tous ces succès, faites la campagne en ligne avec un ou plusieurs ami(s), pour obtenir le succès du chapitre en dément pas besoin de le faire en entier, il vous suffit de jouer tout le chapitre en décontracté puis de quitter et de re-créer en dément pour le dernier niveau de chaque chapitre.

Liste du dernier niveau de chaque chapitre:
- Chapitre 2: Serenity - Guerre
- Chapitre 3: Gateway - Deathmatch
- Chapitre 4: Deimos - Deathmatch
- Chapitre 5: Sentinel - Deathmatch

Online campaign completed
To get all of these achievements, do the online campaign with a friend(s), to get the chapter achievement in insane you don't need to do the whole chapter, just play the whole chapter in casual then quit and to re-create in insane for the last level of each chapter.

List of the last level of each chapter:
- Chapter 2: Serenity - War
- Chapter 3: Gateway - Deathmatch
- Chapter 4: Deimos - Deathmatch
- Chapter 5: Sentinel - Deathmatch

If you want to get this legitimately without boosting or without using bots on your team there are a few things which worked for me. @austex360 's solution worked well but I'd like to add to it as I don't think it's as difficult as people make out to do solo on Insane difficulty.

The key to defeating Akasha is learning where the health and shield pick-ups are on the map. Ideally you want to stop her picking up the Shield Belt and Quad Damage powerups as if she gets both of these she's very hard to kill and they usually spawn within a short time of each other. She will ALWAYS go for these as soon as they spawn so try to pre-empt her where possible.

I personally found the Bio Rifle and Flak Cannon to be more effective against her than any of the other weapons (including the Rocket Launcher). The bio rifle's secondary charged fire was particularly effective against her in my opinion. If you can land the gloop near hear she will usually take splash damage and if you can get a direct hit it will stick to her and quickly drain her health until she's dead even if she has shields. I also got lucky a couple of times where I missed and shot my load on the ground and she accidentally ran into it later which also killed her

Don't stay still and keep running round the map in a circular motion, picking up ammo, health and shields as you go. You will take heavy damage from Akasha in every encounter so it's important to keep your health and armour topped up so you're less vulnerable as she can easily one-shot you if you're weak. There are 3 health pickups on the upper level by where the Bio Rifle and Sniper Rifle are as well as a chest plate shield down the stairs by the Bio Rifle. These are important to keep trying to pick up between encounters in my opinion.

It took me at least 10+ attempts to get this so be prepared for some frustration. I had a couple of very near misses where I lost 20-19 which was annoying to say the least. But stick with it, learn the map and as long as you've got some FPS skills you will eventually get it. Eventually I bet her 20-15 which was pretty satisfying