There is a usefull trick with UDC i want to mention.
Using normal normal special combo twice in a row reduces HP to less than 12,5% (Df rdy). This way its not just much mo safe, it gives you alot of accuracy and you can hit all 6 special attacks. Downside of it is you reduce HP a littlebit slower than 3x special combo ofc but thats just worth it imo. Its very effective against bosses like sil dragon (you do normal normal special to make it sit and repeat instead of 3xspecial and make it sit on ur face) or Olga flow, first face of it you can hit 12 times total because it has 2 targets. Its also usefull on crowded quest like pts, to be a littlebit more safe and have max dmg output AOE