My two favorite series are Total Drama and Epic Battle Fantasy, so...
Baby Yoshi (Super Mario World): Very much loses due to inability to scale from anything (all it did was get carried around and eat things upwards the size of a person without anything really fighting back; that's not mentioning that Ella's animal manipulation can handle the series' super-aggressive bears, so Ella alone would easily keep a baby Yoshi at bay.)
Spongebob: I'd say this one's fair game. At least Sky can handle this (I've off-shoot calced Sky's burps to be within the Megajoule range), though Spongebob's toon force is much more effective than literally anything even Izzy can pull off. I think Spongebob clears.
Everything else utterly stomps.
Epic Battle Fantasy:
The player characters are largely a depends-on-the-incarnation thing, so this'll be a case-by-case basis. Generally speaking...
Baby Yoshi and Spongebob utterly loses.
Miis are likely able to take out early-game stuff like slimes and bushes, but I can't guarantee if they can take anything else since there is no way to really figure out how powerful anything before the bosses are. The only mid-game enemies that are anything special as far as I can tell are Praetorian (who can turn Lance's Ion Cannon against the party) and Poseidon (who is most likely High 6-A depending on how one interpret's Vulcan's statements).
Barney at best should make it up to Akron with the power of imagination.
Not sure if Kingdom Hearts (as in the moon itself) can handle Akron or not, though. It won't be able to handle the EBF3 party, though.
Tails... This looks to be Classic Tails, and I think it's fair to assume he can get through early-game stuff. That and the stomp he'll be dealing with from Lance's nuke will be less utter.
Sonic is literally the big player here. This is Classic Sonic, but its also his super form, which should scale to Modern Sonic's super form. He definitely makes it past Poseidon considering Modern Super Sonic fought and defeated Chaos, who has caused the Great Flood (this phenomenon is shared among mythological texts, by the way). Considering Super Sonic's power varies largely by game, he can either make it past Godcat and stops at God (the super saiyan cat in case you ask), or he makes it up to Devourer likely to die from Existence Erasure due to Sonic's lack of resistence to it and Devourer's superior speed rating (what the heck is Sonic going to do to against things that can go literally billions of times the speed of light in terms of travel and reaction speed?)