matchup from an olis view:
general tips:
+at 1:00 minute warios waft is half charged and will kill you at 1/4 distance of fd at about 80%, the middle at 100% or at ledge at 70%, use the timer to figure out how charged his waft is, and whenever he uses it take note of the time so you can keep track, remember, at 2:00 minutes of charge time is when it is maxed and wario starts glowing, it will kill you at 40-50% at edge, 65% at 1/4 of fd, and 75% in middle of fd(these are all without di)
+you will always want to di+sdi up if you are hit by this move and is probably wario's most effective kill move against oli, super armor easily beats this out if timed right, you can tell if wario is planning to use waft when he either tries to grab you alot and then jump to you and if he jumps to you, runs away in same jump, jumps to you, runs away again, ect. while trying to purely lure you out just hitting your pikmin, always use this to your advantage to lure out his waft and out space it with similar tactics
+warios kill moves for this match will be, in order: waft, fsmash which can be seen and punished easily but will most like be used as you try to recover(from edge or not) or as you land on the ground and will kill you around 100% in middle of fd or 80% near edge, can be super armored and punished like crazy, upair can kill you around 120% from main platform on fd is easily super armored and can be easily seen, i shouldn't have to explain how easy it is to see coming
+at low percents watch out for warios grabs because thney can set you up for nasty gimps with fair or bair wop, if you get caught in either try to whistle through then bair him or di up and towards him then dair/fastfall bair
+don't try to hit wario with your grabs or smashes unless you will hit 100% because if you miss a good wario will always punish you in a nasty way and your chances are smashing/grabbing a good wario are low but if you do get one use the momentum to your full advantage if he doesn't have a great waft oppurtunity
+spotdodge is useless, end of story, whistle should always be used over airdodge, always, sheild at low percents is uselss, it sets you up in horrible positions, rolling is your only decent defensive move in this match so use it occasionally to quickly get out of a bad spot, never ever roll behind or to wario unless he is in air and you need to get to the other side of stage badly
+ban rc and stage strike/ban bf, rc is obvious and bf is a great stage for wario do to his great offensive air pressure game, the best stages in this matchup are fd, luigi mansion, and yi, sv isn't bad but if you banned the two prior stages and need to use a stage strike use it on sv
+purple pikmin are the best in this matchup, they will stop a majority of aerials approaches and give you openings, learn to love them and try to have atleast 3 with you at all time
+wario's bike tires will be you aonly true good setups for kill moves because the hitstun from them will allow you many oppurtunities for a kill move
how to play the matchup:
first off, see what kind of wario you are facing by throwing a few pikmin at him, does he airdodge, attack, sheild, spotdodge, ect. because whatever he does the most will be what you punish the most
most likely wario will start with an aerial approach, don't try to approach wario, just try to pivot grab him and throw pikmin, make sure to throw a pikmin away here and there so you can try and pluck a purple whenever you have time,
for most of the match until wario is at killing percents you will be playing a game of throw pikmin, figure out away to get away from wario, rinse and repeat, if you are being pressured by wario and can't get away from hi you have three main options:
pivotgrab his aerials and hope you get a grab, if you expect him to jump high into the air then attack shorthop upair,
if you expect a shorthop attack either up-b him when he jumps or jump into him with a nair or fair and hope you get your attack off first,
or if you have purples throw them instead, the only aerial that will stop them is his dair
your jab and dtilt will be extremely helpful in this matchup, wario will beat you if he is face up to you if you smash or grab, if he is still aerial and close enough for the jab use it to try and knock him back and follow up with a grab, purple toss, shorthopped aerial, ect., if he is ground level and in the same position try to dtilt thenupsmash if low percents or if he is high enough to be sent into the air i would use an upair
you will have to jump and move alot in this matchup, the minute you start to stay in a small area and not move much is the minute you will lose
when wario is 120% is when you will be able to start and try to kill him, remember, if he auto cancels his aerials you will not be able to kill him with anything or hit him so your best bet is just to try to predict and punish or use bike tires, you have no reliable way to kill him in this match, i already told you about when he can kill you(starting at around 70-80%) so i won't repeat that
when you are offstage you should try to super armor any of his aerials and if you are hit di up because unless it is his clap(upair) his movess, kill, and nonkill ar mainly horizontal knockback
on the edge is the worst position for both of you in this matchup, wario can easily punish you if you jump off, roll, attack, fall down then upair through stage, ect. so just mix it up and try to super armor through any of his attacks
when wario is on the edge if you think he will shorthop off try to fair him right as he jumps or dair if you think he will just jump up but the dair is tricky to do, also it can be down if he hangs on the edge past super armor(im not sure if you can grab him on edge but if you can abuse it as he grabs the edge or stays on too long) if he jumps then and back up if you do this only once per set if even that you can jump and try to bair him when he is below stage for a surprise stagespike, don't do it more then once or you will be punished, you can also just try to keep grabbing him as he touches the ledge
tl:dr version(i know this is long): keep jumping and moving away from wario while throwing pikmin(purples especcially) and don't be predictable
overall i would say this matchup is 57:43 wario's advantage