FLASH - It is the best summoner spell in the game. What more do i need to say? Let you do manly stuff and get away with it. Just some examples: you spear harass him down to 20%. you jump in for the kill, enemy uses flash or flash like ability. You laugh at them flashing after.

EXHAUST - Will let you duel less manly champions. Not as effective as ignite early game, but makes up for it with it's usefulness late game. No one can take on Mantheon with exhaust up.