Hey dude!
Secondaries, lol. I ask that question myself. Weirdly though, not for those characters.
Unpopular opinion, I like those matchups. Why? They're the type of characters that are flowchart. Do this, then do that and if it doesn't work do that.
For Cloud, you know he'll try to wall you out with fairs and nairs. He'll also try to do a lot of jabs, dash attacks and dtilts. My advice, shield then punish. From shield, you can get either jab, utilt, nair and down b. The first three are for combo and kill confirms, the latter for kills.
For Bayonetta, you know she'll either
A. Utilt/dtilt
B. Witch twist
C. Afterburner kick
So Uhm, shield punish again. Di is also much easier now with the nerfs. Best is down and away but earlier percents, up and in for witch twist works as well. If she becomes prone to witch time, throw more guaranteed setups like utilt uair or fair jab dsmash or egg toss fair. Or you can just mix up with grabs. Or do what you normally do but delay, bait out witch time then punish.
Both Bayo and Cloud can be egg tossed from afar, just make sure you stop once their zone can reach your hurtbox. Resume when in advantaged state.
As for kill confirms...
Jab dsmash near the ledge
Jab usmash/fsmash at kill percents
Jab uair/jc usmash/charge fsmash at high kill percents or floaty characters
Jab downb for fast fallers and shielders
Utilt uair at kill percents
Near ground uair uair at kill percents
Perfect shield to down b
Fair (no tech) uair at kill percents
Fair (no tech) usmash at low kill percents
Fair (no tech) bair at kill percents
And of course remember your list of raw kill moves like bair, offstage nair, uair, sour spot fair
Oh yeah, remember both are also bad at recovery so know fair spike setups...
Jab Jab fair
Egg toss fair
Nair fair
Sour spot fair fair
Ftilt fair
Dash attack dj fair
Jab dtilt fair
Or just nair, sour spot fair, bair them offstage so they can't recover.
Lastly, if you see them roll from the ledge, or roll towards the stage and are positioned properly, quick down b punish can work.