#Please note, I'm using op.gg's TFT page. These are simply what has been datamined and may not be indicative of the final piece synergy.
Magic immunity on some of your frontline
Glacial stun on-hit
This is basically Goblins+Knights from DoTA 2.
Nobles give bonus defensive stats
Your backline Gunslinger carries have synergy
Your frontline Knights can block damage
Your guardians are giving extra armour in an AoE
You have Blitz
This build is 100% about buffing Draven.
Imperial has % chance to do double damage
Blademasters have % chance to hit twice
Draven's passive is adding bonus damage and attack speed as he autos
Attack speed bonus from Wild
Somewhat of a frontline in Shapeshifters, Shen, and Darius
Strong assassin line-up
Great brawler + Glacial synergy for a beefy front line
Attack speed buff for your assassins/Wild
Armor reduction from Void for your assassins
Extra bodies from Elementalist
Full assassin synergy
Draven for Imperial synergy with Katarina
Brawler synergy for front line
Void synergy for armor reduction for assassins and Draven
Wild synergy for attack speed Draven
(Feel free to swap out Kassadin for Cho'Gath for stronger frontline)
Phantoms reduce random enemy to 100 hp.
Nobles for free defensive stats
Knights for tanky front line that blocks damage
Rangers get bonus attack speed (Vayne W)
Guardians help keep Knights alive with their bonus armour
Yordle evasion is always really nice, especially since Kennen is a Ninja
Glacial autos stunning is honestly just a bonus from Knight+Guardian synergy.
Lulu ult will help keep tanks tanky or Vayne Vayne-y