Top: Anyone who can be really tanky
Mid: Twisted Fate
ADC: Draven (Ashe can work too if you are more comfortable with her)
Mid: Destiny Gives vision of every enemy champion and allows TF to teleport anywhere in a huge range. Use this if someone is getting gamked, or to gank an enemy who is low.
Jungle: Rek'Sai has an ultimate, Void Rush that allows him to burrow to any cave opening he places on the map, which means he can get to team fights fast, help when a teammate is getting ganked, or gank an enemy who is low.
ADC: Draven's/Ashe's ult, Whirling Death or Enchanted Crystal Arrow, is a global skill shot that does a lot of damage to enemies, use it if an enemy is low, but you won't be able to catch up, or if your teammate just needs that extra help but you can't run fast enough.
Support: Soraka's ult, Wish, is a global heal, use it when multiple teammates are low, or when in team fights to give teammates that extra health that can turn the fight your way.
Pros / Cons
Can easily defend if someone gets in trouble
Weak early game
Small front line in team fights
Very ultimate reliant
This composition is very anti-gank.
For example, if your top laner gets ganked, Twisted Fate can teleport with his ult to help, while Soraka heals your top laner. Meanwhile Draven's ult is on the way to hit the opponent. Your whole team can help on a moment's notice with this team comp.
Make sure to have good vision of the map, I can't stress this enough, so many teams in lower elos don't place many wards. If you have a lot of wards, you will be prepared for the gank, with this extra time, TF can tp faster or Draven can get his ult off faster.
For top laner, take Teleport So you have a global presence even though you don't have a global ability.
And Heal So you can tank team fights longer.
For Twisted Fate (mid lane), take Ignite So you can do a lot of damage and even possibly kill after you die.
And Flash so you can dodge skill shots or get a better position for your Q.
For Rek'Sai, take Smite Because this is a must have for a jungler.
And Heal So you can heal while fighting creeps at low levels.
For Draven/Ashe (ADC) take Flash To get away from ganks as you are very squishy.
And Heal because, again, you are very squishy and want to stay alive as long as possible.
For Soraka (support) take Heal As it heals you AND AN ALLY, so this doubles as a heal if your ADC is low
And Ignite So you can do some damage to help out Draven/Ashe a little.
This comp is very good, but can take some getting used to. If you are in a lower elo, remember to ward. Also, always look at the minimap so you know when your teammates are getting ganked.
Hope you all enjoyed this guide and will use this team comp in the future!