Thoughts on Jack of All Trades Bel?
Full disclosure before I start. I don't play any champs that run Jack of All Trades, so my sense of what it's actually for and how good it is basically doesn't exist. This is just an idea I had. The whole thing relies on the fact that AP isn't a completely wasted stat on her now, so she can buy Dark seal and not feel too bad about it.
Build either Bork or Kraken, whichever you prefer. Grab a Dark seal early. After your first item, go Merc Treads into Serrated Dirk + Crit Cloak to build into Collector. Between all those components, you hit 10 stacks before your second item is finish. From there, you can sell Dark Seal for something like Black Cleaver or Death's Dance. If you went Bork, you could go Hull Breaker third.
Alternate build: Build whatever first item you want. Kraken, Yun tal, or BORK with Dark Seal and Mercs, then cloth armor + glowing mote to build into Death's Dance. This gets you 10 stacks faster since it is cheaper than Dirk + Cloak. This one's probably more consistent. Get you the 10 JOAT much much earlier.
Obviously this is rushing JOAT as hard as possible. No clue if that's actually optimal because, again, I've never played a JOAT champ.