If by Ultimate weapons you mean beat for each chacracter then I can answer that.
For the Hero get the ultimate key from Marta's house and get the rusty sword from trodain. Mix that with an orichalcum and a slime crown. That sword (liquid metal sword) is Angelos best weapon. But if you mix that with the dragovian sword after defeating the vermillion dragon, you get the Hero's best weapon, Dragovian King Sword.
For yangus, get the conquerors axe from the slime mountain (accessible after getting the godbird soulstone) and mix it with a warhammer and something else.(i dont know what it is). You now have the Uber war hammer, Yangus' best weapon.
For Jessica, earn 200,000 tokens at the Baccarat casino and exchange is for a Gringhams Whip.
And Angelos second best weapon is the hell seeker, in the troll maze available after beating rhapthorne in his castle.
Good bye everyone, it's been fun!
Special thanks to ED_, superman4u, and Cross Stinger
Credit for the Siggy goes to shadow slayer