about Roald being lazy with GP: first, make him go relentless (he will likely place an Impale debuff over Yosuke, making all attacks deal 10% more damage, which will make your quest easier), and when you start needing GP, shift Roald to defensive for one turn - he will 100% cast GP (unless it's on the cooldown, it has either 4 or 5 CD). Also, IIRC Nightmare's Over is not resistant to dispel, so if your ST is level 2 or higher, it will get dispelled because then ST dispels more than one buff (equals to ST level).
About Epiphany killing Yosuke: Wow, a rare move of self-sacrifice :) And, I don't remember does Yosuke heal for a lot? If not, you can shift Confinement with Epiphany in the order (to have Shock Coma offset one less turn of Epiphany's damage) and then spam Dark Echoes until you die. Or first raise FW over self, then spam Dark Echoes. I expect they will go over 4k with Psychopath form on, and even if not, they will stack to make Epiphany do more DoT.
About hydraulic having more vitality than others: So what, all you are having there is a punchbag. I said, AE+SB+Withdrawal are 30k on a speed bio, focus or no. You waste 1 turn for MF, you have 1 turn to do something about impending DOOM. Heal self, or what? Even if not, this attack can be directed not against your Sonny but your Roald or Felicity, just for the lulz. Also, Leading Strike is one heck of a damage on a bio, it has a good chance to crit, and physical piercing is still there within some of the skills. And bios have Adrenaline to amp self. Well anyway, speed bio defeats a cold mage hydro any day of the week.
About other builds vs hydro - first taking lightning psycho. Shock Coma lasts 4 turns, which your hydro happily slumbers through, by this time you lose your allies. If no stuns, well, there's still Electric Storm 3/3, equipped twice (can do better) that does comparable damage to your MF/FF/other ice skills. No Overdrive in PVP of course :) Second build - poison bio. Well, not much I daresay, but LS does a hefty punch, since poison bios amp strength, and even without Shadow Blend and lotsa speed, Withrawal 4/4 is a greater damage dealer along with self-healing aftereffect (~20%HP/turn combined with Integrity). Also, Break does 220%str and takes no focus. Third - hot build hydro. Demolish-Demolish-Decimate-Decimate, and you suffer 4 attacks for 3k-4k each and 2k/turn DOT. No focus requirement, note that. And Vapour Cannon, yeeees.
Yes, by the way, if no stuns as homerule, cold mage hydro has only 6/8 turns of focus lock, as he's forbidden to use Flash Freeze. So, any char surviving 6 turns has 2 turns of ROCKING your hydro down. Unfortunately, cold hydro is not a PVP build, but a PVE build.
Retrograde (subversion), you say? Over yourself, it lasts 1 turn, which can be used by your enemy to whack someone else. Or skip it, or heal self up. I have however heard about a build, that uses Icewall self-attack-Icewall self-attack-Subversion self-repeat, but in PVP it's countered with Disrupt or Regulate, and a psycho could just FW self in midtime, making the battle a stalemate.
About posting codes - well, you copy it from the game, leave an empty line (Enter, Enter) before, paste, leave an empty line after. Or make a post containing only code. Copying it from the forum is to use triple click to select the entire set of symbols.