Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
To say it quick and simple: Tryndamere has hudge bonus to bloodlust and spinning slash from AP, why not make use of it? Lich Bane is our key item (yeah i know, i know, this mana addition is useless, but it's unique is great for our hybrid), witch makes sense pumping some ambility power. That's why you shoud get it first, after boots. I've done some maths and calculated that Infinity edge makes sense from the moment u have in total over 45% crit chance(with IE) . So don't get it too soon. Most Tryndamere builds go for runes that add crit chance, or crit dmg. Because we don't have typical crit items we have to make it good with runes. Runes that incise crit dmg, are rentable if you have 65% or more crit chance. Try it, and help me make it better. Last two items can be changed for some cd reduction items, like Spirit Visage and The Brutalizer. Just don't go for atack speed, we want every tack be buffed from Lich Bane, instead if you want add atack damage or AP.