Ah, the Ninja...a type of Warrior so stealthy and powerful it needs no support of its own. It all started with Armed Ninja, whose effect now is more important to have as ever, and Ansatsu, but the Ninja was just another Warrior until Invasion of Chaos...the revolution of the metagame as we know it today. You might remember this monster from the Dungeon Dice game on the Yugioh cartoon between Duke Devlin and Yami Yugi....Strike Ninja was the 2nd-best monster Yugi used in that match (gee, I can't remember what his 1st-best monster was ).
Its effect lets you remove him from play until the end phase of the turn. You may look at this and ask "But how is that good, Wolf??" I'll tell you.....Strike Ninja's effect is also Multi-Trigger. This means that you can use his effect during either player's turn AND it can only be chained to with a Counter Trap card like Divine Wrath. Also, Strike Ninja can dodge card effects like Snatch Steal, Torrential Tribute, Cyber Jar, and Bottomless Trap Hole.
Strategies and game play:
You can start your attack with Strike Ninja and see how your opponent will react to the attack. If they chain Magic Cylinders, for example, you can use Strike Ninja's effect to remove itself from play and you won't take damage from Magic Cylinders...because the monster it's targeting isn't there anymore!
Strike Ninja can also be defensive. If you have Strike Ninja on the field and some other monster(s), and your opponent wants to attack to get rid of your pesky ninja, you can use Strike Ninja's effect to force the attack to one of your other monsters...say, for example, a face-down Morphing Jar ;).
Combos with other cards:
One combo with this card would be Fuhma Shuriken. The shuriken would boost Strike Ninja to a 2400atk monster, and when you use Strike's effect then the shuriken would deal an extra 700lp damage to your opponent when it's sent to the graveyard.
The most popular combo with Strike Ninja (and the main reason he's run in a lot of decks) is with D.D. Scout Plane. If you remove a D.D. Scout Plane from your grave for Strike Ninja's effect, that Scout Plane will be special summoned to your field at the end of the turn it was removed (this also makes DD Scout Plane good bait for your opponent's Nobleman of Crossout). With the added monsters on the field, you could tribute them during your next turn to summon strongers monsters like Jinzo or Ancient Gear Golem, attack with them, or get a nice little boost from United We Stand!
Ways to counteract it:
Strike Ninja has pretty low attack and defensive stats of 1700atk and 1200def, so he's easy pickings for a strong 4-star monster like Luster Dragon or Goblin Attack Force. Also, you could chain Divine Wrath to the activation of his effect to make the opponent lose their Ninja AND the monsters removed from play to activate its effect.
What a lot of people don't understand is that a Ninja deck doesn't focus on over-powering your opponent, but on deception and manipulation. This means that Strike Ninja's low attack and defense rating shouldn't come into play as a weakness if you use him properly. Plus, having the ability to dodge your opponent's effects is VERY handy. And being a Warrior type monster and having the support of all other Warriors is never a bad thing nowadays.
His low attack and defense rating, the fact that you need 2 DARK monsters in your grave in order to use his effect. Other than that, it's really quite a serious card to be dealing with.
In America, it's been an Ultra Rare in Invasion of Chaos and Dark Revelations 2. In the Japanese game, it's known as Swift Black Ninja, I believe.
In a general Warrior deck: 5/10
In a DARK monster deck: 8.5/10
In a tribute/spirit monster deck: 8/10
In a NINJA deck: 9.95/10 (there's a reason why I chose 9.95...turtle power lol)