Sven

Sven the Rogue Knight is a versatile melee strength Hero with high physical damage potential and an effective disable. He can be played in many roles, though he is mostty known as a support or a carry. While Sven is a strength Hero, he uses his spells to gank and often kill. This makes him a somewhat mana intensive hero, resulting in him having a major problem with his mana pool. Sven is an item-reliant Hero, as he needs farm to advance into the late game, but his ultimate causes him to grow to be a powerful hero as the game progresses. He is a great support in the earliest parts of the game, can excel as a ganker in the midgame, and, with enough farm and kills, he has a potential to be a strong late-game carry. Due to his many roles, he is classified as a semi-carry. He has great crowd control and a very high damage potential thanks to his ultimate, which makes him a great carry. Once activated, few can withstand the almighty strength of the Rogue Knight.

Gameplay
Sven is a very item dependent hero, so getting the right setup is crucial to victory. During the early stages of the game, players should get items that provide a way to regain mana, such as a Magic Stick which can be later turned into a Magic Wand, Ring of Basilius, or Arcane Boots if going for early game dominance (else build power treads and keep set them to intelligence). These items will make sure you will have enough mana when it's needed and makes early ganks easier. During the middle-game phase, the player should base his item setup on the opposite team's hero lineup. If the enemy team has potent disablers, such as Shadow Shaman or Crystal Maiden, then getting Black King Bar would allow you to decimate your opponents without getting disabled constantly. If the enemy team has Carry heroes, like Drow Ranger or Spectre, then getting items like Vanguard or a few Bracers would be a good investment.

Now Sven shines with the use of his ultimate, God's Strength. However, it only lasts for so long and Sven, being a strength hero, has low attack speed. A great way to compensate for this is by getting Mask of Madness early on. It provides an immense attack speed boost, along with lifesteal, making Sven dish out a ton of damage in a short time and heal himself if need be. To further capitalize on his ultimate, getting Crystalys and later upgrading it to Daedalus, allows Sven to dish out insane amounts of damage during the span of his ultimate and Mask of Madness' attack speed boost. Of course, alternate item builds are possible and encouraged, but the item build above synergizes with his skillset very well.

For the late game, items such as Assault Cuirass or Heart of Tarrasque help to solidify Sven as a mighty tank. Otherwise, getting items that further increase his damage would be a good idea; these items include Monkey King Bar, Skull Basher, Radiance and Desolator (assuming you don't have Mask of Madness, as that would conflict with the lifesteal unique attack modifier).

Tips

 * Early on Sven has very low mana, so building mana boosting items may be a good idea.
 * Sven should concentrate on farming during the early stages of the game, and maybe try and get first blood if he has a lanemate with a disable to help him.
 * Drum of Endurance is a great item as it meshes well with Sven's role and play style.
 * Take Stats over the two other skills instead if you want more Mana, Attack Speed and Strength to increase the bonus of God's Strength early on and to help sustain your mana for using skills.
 * If you prefer the Initiator Type, get a Blink Dagger. Blink to your target and stun them with your Storm Hammer, make sure you activate God's Strength immediately.
 * Avoid leveling Great Cleave early on, as it will greatly push the lane towards the enemy tower making farming more difficult. Warcry gives all of the bonus movespeed with just a single rank, making it a great one-point wonder early in the game.

Trivia

 * In an earlier version of Dota, Sven had a fun name which was Arnold Schwarzenegger, a reference to real-life actor.
 * The phrases "Twas only a flesh wound." and "It was but a scratch." are references to the Black Knight, from "Monty Python and Holy Grail".
 * Sven is left-handed.