NOTE- I will finish this build as I use AP Trynd more.
NOTE- The item build is sequenced, use your own discretion in which pieces you'll need to get when past the Sheen.
update 8/6/10 - Added guide section, updated item build as I saw needed, changed to def. tree masteries and changed seals to dodge
So to get started, this is a weird build. You may even look at it and think, "What the hell, this would never work."
But that's the strange thing, it does - but it requires a team of other high burst damage chars.
As you may have assumed, this is a build based around spinning slash. What makes it work? Every time trynd crits, the CD of spinning slash is reduced by 2 seconds. With an already fairly short CD of 8 seconds, this assures you get in multiple nukes when popping endless rage, and can be extremely devastating in team fights.
Now onto the guide part -
At the beginning of the game, you'll want a lane partner who can deal good damage, and preferably also disable. I start by getting an ability tome and leveling up spinning slash. Depending on your lane enemies and partner, you may not want to do this, as if you want to go for beginning gank and have no disable, mocking shout is practically a must. So you're laning, farming, not getting killed and you get about 820 or 1100 gold. You'll want to go back and get your sheen now, and boots if your money allows it.
Upon returning to your lane, it will hopefully be pushed to your tower in your absence, and now it's time to do some killing. In fights, you want to maximize the use of your sheen. Start with a spinning slash, hit, mocking shout, hit, at this time, you may have bloodlust stacks, use them to heal and get another sheen hit, and then finish them off with a spinning slash/sheen hit. Did i mention don't forget to heal? Also, if you have a choice between spinning into a kill to die, or spinning away, choose spinning away. It's not worth feeding your enemies, and you don't want them to catch on to what you are doing. Until it's too late.
Now you'll have some gold, and you want to get your mejais. You haven't died yet, right? Because you still don't want to die especially since you're getting mejais. There are very few situation which I can justify dieing as AP trynd, his massive heal, his ult, and his spin are more than enough to ensure that you do not bite the bullet in depressing ways.
So you're well into mid game, going into early late by now. You should have around 8-12 stacks, your boots of swiftness, your lichbane, and you'll want to be working on your zhonyas or phantom dancer. Why phantom dancer in an AP build? Because you need that 30% crit and 15% move speed. The crit is necessary for ensuring as many spinning slashes as possible before popping endless rage.
During this time, DO NOT NEGLECT YOUR POWER AS A TOWER/LANE PUSHER! You will take down whole creep waves in one spin, and then on the next hit your lichbane will do mass damage; especially to towers. how do you maximize lichbane hits on towers? Well it's fairly tricky, really. Spin whenever it's up, and kill any incoming creeps around the tower with it to get bloodlust stacks, then use them immediately for another lichbane strike. On a normal tower push, you should be able to get at least 4 easy lichbane hits.
So moving into late game - There shouldn't really be a problematic late game. Participate in team fights, taking advantage of your ability to spin through multiple enemies at once. Don't be afraid to kill off enemies with your spinning slash ability which may be called a "ks" you do this to prevent escapees and gain easy bloodlust stacks to keep yourself healed, if you haven't had to pop your ult yet.
Any comments would be appreciated, and if you down vote, tell me why. I know I haven't finished this yet, but there will be an update within the next few days.