First of all I would like to say that this is meant to be a fun build not a competitive one and that for this to work in any capacity you need a team that can do decent damage. Now that you understand this I can tell you about the role of the kamikaze. As kamikaze your job is to get as close as possible and deal massive amounts of damage before dying, you do not care about your k/d at all, all you care about is doing as much damage as you can so your team can come in and clean up. Karthus and Tryndamere are excellent examples of this type of champion when built right. Twitch is viable for this role simply because of his cloak and penetration ulti which, along with a hurricane allows him to deal massive amounts damage to an entire team before dying nearly instantaneously due to him being super squishy.

First of all, in order to succeed you will need to get as close as possible to all members of the enemy team in order for maximum damage to all members and for your hurricane to be not a useless waste of money. With your cloak you can take some time to position yourself so to ensure every one of the useless scrubs opposing your godlike power are within your range of attack. Of course this can be countered by a oracles so consider using your barrier to get close enough or replacing revive with flash to close the distance. Obviously something this insane requires some initial set up to have any chance of working, make note that you are useless without your items so play extremely safe early game and encourage your team to play defense until you gain enough cs for your items. Play like a normal adc and backdoor often (Because you're Twitch and only noob Twitchs can't backdoor then escape without a scratch)then once you get the majority of your items you should attempt to convince your team to bait the enemy into a teamfight. When the fight starts you will cloak and position yourself as close to their HVTs (AD Carry, AP Carry, any of the champs your idiot teammates fed) as possible then reveal yourself with an flask of poison and an active ulti. When the enemy (and your teammates) gets over the initial surprise of your martyrdom and begins to focus you, you hit your barrier and laugh at their attempts to hurt you. You will die soon after, Pro Tip: Expunge right before death. Hopefully you took one or two of them down with you and did good damage to the remaining champs, now your worthless teammates can cleanup the scraps you didn't decide were worthy enough to take to hell with you. If you are having trouble with CC then take cleanse instead of revive. If you managed to keep revive then pop that to help your team push while the enemy is waiting to respawn, or if any remain, repeat the process.
Congratulation! You now know how to sacrifice yourself for the cause and will likely be a better person for it. If the rest of your team isn't completely useless then this strategy will carry you and your janitors/teammates to sweet glorious Victory!

Pros:
Amazingly Fun
Helpful to your team
Confuses the enemy
Diabolical
A actual use for Runaan's Hurricane
You will have more assists than your support

Cons:
Your k/d ratios will be absolutely disgusting, but luckily for you only scrubs care about that.
You will have more assists than your support