Disgaea: Hour of Darkness Guides and Walkthroughs
One of the many different aspects of Disgaea I would have never figured out on my own without watching videos or reading guides would be character stacking. This is a simple and extremely useful tactic which you can use to make it all the way across the map in the Item World in just one turn.
Literally all you have to do is Lift one of your teammates up and then using another character that isn't holding anyone, Lift the character who is holding someone. You'll now have one character who is holding two characters. You can do this 9 times if you want, having your entire team deployed on the grid, all held by 1 character in a huge tower.
After all of your characters are stacked up in a tower you'll have to Throw them across the map in a single turn. If you end the turn while holding all of your characters, the character at the bottom will take a huge amount of damage and very likely die.
It's important you keep in mind the downsides of doing this too. The first and most important downside is if you "End Turn" before advancing to the next map, the enemies on the map will wreck havoc on your characters. They'll be spaced out and typically not in defensive positions.
The second most important thing is to make sure you check the entire map and plan your route before you stack characters. If you have to Throw your characters up a high cliff face or across a large gap, you're not going to want someone with poor stats doing that.