I hold the record time for beating the final boss on twisted difficulty. I would recommend that you use Shadow, since it's the right balance of weight so you don't get knocked around easily, but still has an effective special for the first stage. Also equip machine guns since they're most useful for the first and fourth stages.
For the first stage, just fire your inventory and hit the head with two alternate specials at close range. You can absorb the flamethrower to gain a special, but you can also just hang back a bit longer and wait for the special to regenerate.
The second stage is probably the easiest stage. If one of the chainsaw henchmen jump on your vehicle, just drive into one of the bumpers to knock them off. There's plenty of opportunity to regain health by enabling the health bumpers too, though you probably won't need them since there's health in the next stage as well.
The third stage, the gauntlet, is also relatively easy. For a number of the obstacles, the timing is such that you can throttle it straight through whole sections. Don't worry much about the timing for the first two sections, since there's a health pack right after and you'll likely regain most of what you lose. The wrecking balls are probably the most deadly since they can knock you off the track and make you respawn back at the start. Just wait for the first to the path, creep forward, wait for the second to pass and then book it past all the other wrecking balls. The fists at the end can insta-kill you, so be careful there.
For the last stage, practice makes perfect. Try to make the best use of your weapons that you can, and make sure you have a clear shot since the AI will even doge homing missiles if they're in motion. Mega guns are extremely effective here, but make sure your target is just hovering when you engage them. Pay attention to the controls in the top left if you're unfamiliar with flying Talon. Turbo and quick ascend/descend is extremely useful. If you've used all the health, there'll be random health that cycle spawns with other weapons under the machine, but be cautious of the turrets that will slowly sap your health under there. When dropping the minions, there's a cone that appears showing where you need to drop for them to home into the opening.
I'll also toss my video of beating that level here. Obviously it's designed to complete the level as fast as possible, and there are some risks that would be unnecessary for someone just trying to beat the level to take, but it shows that the level's actually pretty easy after some practice!