Barry J Bluejeans is a lich necromancer, capable of casting the paladin/cleric spell Command, who is fluent in thieves cant and identifies as a fighter when his memory is wiped.
Barold what the absolute fuck
Barry J Bluejeans, on top of all of this, is also an item artificer (just like everyone else on the Starblaster), a bond and interplanar scientist, and plays the fucking piano, so at any point in time this motherfucker could class as a bard if he really wanted to.
What is Barry?
All the power is in his jeans. He’s just possessed by them.
sildar hallwinter is a fighter/bard multiclasser
barry bluejeans, sentient pair of pants possessing sildar, is the weird wizard/paladin multiclasser.
Actually, in 5e, none of that is even weird, even if you stick to just the Player’s Handbook, no extra guides. His ability to play the piano is probably from his background, which would have to be Entertainer or Outlander. Barry’s a Human, so he can get a feature at first level, but if he didn’t, he gets the option again at 4, 8, 12, and 16. When he gets that option, he can take Magic Initiate, choosing Cleric, so since Command is a first level spell, he can cast it once per day for free, and using wizard spell slots otherwise. He can use another of those features to take Linguist, which allows him to gain three languages, one of which could be Thieves’ Cant. Another feature gets him Weapon Master, allowing him to wield any four types of weapons, and then he can take Lightly, Moderately, and Heavily Armored, to completely pass himself off as a Fighter by wearing any armor he wants. So no, Barry’s not multiclassed, he’s just built by someone who really knows their way around the PHB