Lucario/Diddy Teams
I really didn't like Diddy at first because my partner was a little inconsiderate with the bananas. Once you get used to it, though, you can really start to abuse the bananas yourself. At closer ranges you can banana > fsmash, and at longer ranges, you've got....
AS + Bananas. This is one of the best things this team has to offer. Your opponents will eat SOOOOO many FCAS if you set it up right. The main strategy here is to try and get on the opposite side of the stage and keep your opponents in a pincer between the two of you. Rain down on them with AS while the diddy showers them in bananas, and watch as it destroys them as they trip and die Even if they roll, the size and speed of the AS hitbox does a very good job of techchasing them. With a little prediction, they eat it almost every single time.
Lucario's ability to wall off zones, with large extended hitboxes like Fsmash and AS, works very nicely in conjuction with Diddy's bananas, because you can really control the stage. This team is exceptional at laying on the pressure. Diddy forces them into disadvantageous positions, and Lucario severely limits their safe escape options. Consider an opponent that is tripped inbetween Lucario and Diddy. This guy is in a horrible position. If he rolls toward Lucario, he risks eating an Fsmash. If he rolls backward, Lucario can launch an aura sphere at him, and they almost always will eat it if they try to roll away from it (see above), OR they'll get hit by a smash or grab from diddy. If they get up attack, they'll probably eat an AS anyways, and if they stand up normally, they've got to throw their shield up to avoid an oncoming AS or banana, leaving Diddy with a good opportunity for a grab (which they absolutely love to do after chucking bananas, trust me)
Overall, this team is fairly versatile, with Diddy being able to effectively fight a LOT of Lucario's bad matchups such as GnW, Marth, and perhaps DDD.
Some things you have to watch out for:
Killing can SOMETIMES be a problem. Try to make sure that diddy lives longer than you do, because you'll get a nice aura modifier bonus. Diddy isn't exceptionally heavy, but luckily he has a versatile recovery. Lucario is going to be the one responsible for most of the killing that goes on, ideally. The risky part is that if you get killed before your opponents do, the team suffers greatly in terms of killing power. It is recommended that both members of the team be very good at DI and general survival.
In general, you want to stay OUT of Diddy's zone. Lucario is fairly string/combo-oriented, and eating a stray banana in the middle of a combo really sucks. :/ Staying out of his throwing range is generally a good way to prevent this, however it makes it more difficult for the team to help eachother during edgehogs and 2 person grab-combos because, in general, they are farther apart.
This team combination has a sort of learning curve of its own. Diddy's banana play makes him a sort of independent type of character that would not expect to do amazingly well in doubles. It takes some time to realize how to best adapt to the Diddy style of play, and it generally means you will be playing passive-agressive. When I first tried this out, I hated this team, but now I think it's actually quite complimentary.
Anubis is either difficult to use for this team, or my partner doesn't really understand the principle of the strategy. Diddy generally gets sucked into the fight, because in my observation he is very momentum-based, or perhaps he's not the best planker in the world. I really don't know too much about Anubis for Lucario/Diddy.
One of the best stages for this team, in my opinion, is FD. The stage's size gives diddy the space he needs to set up his bananas without tripping his partner too much. I also find that I myself can use his bananas to great effect on this stage. Japes is a fairly notable counterpick for this team, as Diddy's monkey flip makes him good at recovering against the water, and large blastzones are good for lucario (although it's possible I really like this CP because I sub Falco *shrugs*). Pictochat works decently for some of the same reasons as FD, and frigate, depending on the Diddy's preference, is also a pretty good counterpick.