Soraka + Yi= Insane Harass team so the opponent cannot harm
You have Soraka Starfall doing damage and -Mag Def. + Yi who can do a free harass with Alpha doing magic damage. Pretty much they cannot farm. Soraka give -magic armor, pretty much your whole team has Magic Damage.
Janna + Garen= Enemies get close to creeps, Janna slows for 4 second with 25% mv spd. Garen Judgement and auto attacks= dead. Janna has a slow and stun. Hurricane is kind of like a stun.
Mordikaser: Mid. do I need to explain.
2 Tank DPS
1 Uber Healer/Negative Magic Armor
1 Main Carry DPS/Tower killer