Get potion and ward if you have the money/space left over after buy.
Make sure you hit the slam, use flash if needed to get in position, slow them once the stun wears off with either cutlass/hextech or exhaust. best to save exhaust so you can ult someone and exhaust them then chase the squishys, or exhaust high damageer, only use for slow if item on cd and no red buff.

Always try to use your ult on someone who has weak damage and little or no CC, they should also not be the main focus so your ult stays up for full duration - then go after their squishy dps, you should take all the agro and your team should follow you in. if they run use your slows and turn on anyone that gets left behind.

This build stacks run speed and devestating blow, with your W move, trinity force, boots, phantom dancer, and shiralias, you can run very fast in bursts. use this with the slow as needed to get the wall slams. after this your devestating blow will have attack damage +150% damage from trinity + bonus magic damage from Q + 8% of their hp as flat magic damage, if this crits it is also increased by the Infinity edge, making for a very strong hit. If they survive this you have the speed to keep hitting them with very fast leeching attack with slow chance, and repeated Q moves which also leech, and will crit around 1500.

Because damage is also split between magic and physical they cannot stack one type of armour against you. W is built before E becuase slam will not always hit, it can be used on minions to get in or our of battle though, also useful for nocking champs out of charge up/channeling moves, like kat ult. W is more useful at higher levels though, for sprinting out of danger or into position, also gives very nice auto attack buffs, which will pay off far more than a higher damage slam.

Best played in duo lane with someone who is on the ball so they will attack when the slam hits. Use the bushes, stand on the outer edge so when the enemy enters it they pass you, and you are behind them, slam will then take them into the wall. Farm last hits as much as convenient, but kills are more important, your lane partner will be able to farm if you stand in bush as cover, you will get the XP and gold from philosophers if enemy is careful.
Dont be afraid to take a bit of chip damage as you have early health regen.

*Build requires in fight micro-management skills - but is great fun for it.