Sparks gear is completely unusuable garbage, get rid of it asap.
RDM is very hard to gear up because this months ambu doesn't give gear for it and psycloth gear is awful for mages, the only usable mage gear doesn't exist until merlinc which is at the end of the tier of progression you'll be doing inside of reisen. (you missed jhakri ambu month so you're screwed for months, nice design SE)
You'll want to get despair set from t1 escha-zitah(
https://www.bg-wiki.com/bg/Category:...a_-_Zi.27Tah_4) for melee RDM and eventually try to work on augmented taeon gear with triple attack from alluvion skirmish or some carmine abjuration set from escha-ruan(
https://www.bg-wiki.com/bg/Carmine_Armor_Set), most notably the pants. I recommend either RDM/NIN or RDM/WAR(fencer bonus + berserk). /WAR might be your best option simply because RDM's attack is obscenely low without outside support and savage blade hits hard with fencer(even only rank1 fencer) Melee is RDM's best role atm and should be the preferred/proper way to play in a lot of situations, melee while doing supporty things like haste2/refresh/dia3/distract/addle and only casting para on darkness magic bursts and curing in emergency situations ONLY.
Most of these enemies aren't very hard to kill but I don't think you can solo them as RDM even with trusts, I suggest making friends or finding 1 or 2 other people(you shouldn't need more than 2 more people) to tackle these NMs:
https://www.bg-wiki.com/bg/Angrboda:
This guy is kind of tricky. He's basically a DPS race so keep up barfire and stoneskin and try zerg him down asap once he gets sub 50%, and especially sub 50%. He starts to spam a high AOE fire based attack called volcanic wrath which gives you max HP down, and at 10%(I think, or 5%) he'll use it and it will have a VERY VERY long cast time(I think there's some mechanic of casting water nukes reduces the damage of this, but I have no idea) and it'll basically 1 shot all trusts + nearly 1 shot all players, so he has to die asap after using this because he'll continue to spam it. He also has crystal rain which is single target fire damage and hurts bad, as well as heavy strike which he will combo with mighty strikes(100% crit rate) and can 1 shot un-prepared players.
Personally I did him as DRK/SAM + WHM/SCH and 4 trusts(koru, seltheus, shantotto, ulmnia) and with arcane circle(4:30 uptime on 5 minute cooldown) and arcane crest plus keeping up seigan + thirdeye for heavy strikes the entire time and swapping to PDT gear for heavy strikes and MDT gear for crytal weapon/volcanic wrath he was easily(but stressfully) doable in full reforged af+1 DRK gear. I would save arcane crest for sub 50%(when he starts to use volcanic wrath) and arcane circle around 80% or so, making his attacks very managably cured by a WHM player. I did not try him with apururu or yoran so I'm not sure if they're capable of healing it. The body this guy drops is worth augmenting to max ASAP.
https://www.bg-wiki.com/bg/Ferrodon:
I have no idea how to fight this guy and had a vajra thief 1 shot him for me. He wasn't very scary I suggest trying to dispel his boiling blood and zerging him down asap, perhaps try to spam water nukes backline with a staff to remove his stacks and proc him or MB a high tier water nuke on him.
https://www.bg-wiki.com/bg/Gestalt:
This guy is super annoying. Even with a vajra thief 2 shotting him he was annoying, I suggest subbing rune,keeping up stoneskin and running away whenever he chainspells(80/60/40/20% hp) and spam curing the tank until it fades. Turn away when he cast dread spikes IMMEDIATELY or you will die asap and watch out for curse + impact combo which can 1 shot the tank, especially during chainspell. The easiest way to kill him is to zerg him down, notice the trend? These mobs are super scary but killing them asap is the best tool for dealing with them, imo.
https://www.bg-wiki.com/bg/Cunnast:
Fought this guy with a vajra thief as well, but he wasn't that bad. He can randomly conal 1 shot with breaths and has an AOE paralyze. Might want to RDM/SCH for this guy and help paralyna. Not too bad to deal with if your tank has a decent amount of -DT or -breath damage taken gear and rune subjob. Keep the tank topped off and keep paralyna off anyone in range of it. Simple.
https://www.bg-wiki.com/bg/Revetaur:
Haven't fought. Good luck. I assume using a trust to tank him while you zerg him down might be the best option.
For caster gear you'll want vanya legs(until you can get psycloth legs and augment them), psycloth body, psycloth gloves and reforge +1 RDM hat as well as relic +1 boots(kinda expensive). I'm not sure what a better option for boots are. Get 2x shiva rings for nuking and leviathan/aquasoul/Mediator's Ring for enfeebles. Try to get this staff asap as it's the best you'll be using for a WHILE:
https://www.bg-wiki.com/bg/Marin_Staff it drops from
https://www.bg-wiki.com/bg/Vedrfolnir which is pretty annoying to fight TBH:
He spams stormwind(wind damage?) a bunch of times then ends the combo with a deadly dive which is 1.2k+ damage + stun on a single target(conal?) but the most annoying part is he casts feather barrier which gives him OBSCENE evasion and you won't be removing this without a blue mage or bard with light dispel. I personally don't even know if their dispels work because I didn't try but normal dispel/darkness dispel is completely unreliable. Shield/full break causes his feather barrier to have "no effect" but since he's wind based it's unreliable to stick the debuff for any extended amount of time. He is also basically immune to distract since it's wind based. A RDM/BLM using elemental seal to remove feather barrier is a reliable way to remove feather barrier but it has a long cooldown and he might recast it again after. Weapon skills seem to proc him and freeze him but it's random and not reliable. Best way to deal with him is just to zerg him down asap and I duod him NIN + WAR with trusts.
If you have problems getting marin staff from him use your
https://www.bg-wiki.com/bg/Kupon_W-SRW to pick up
https://www.bg-wiki.com/bg/Lehbrailg_%2B2.
Cure potency gear is easy, buy a Nefer Kalasiris off the AH for cheap, get a roundel earring off AH(can try to find someone selling these via /yell) and a
https://www.bg-wiki.com/bg/Mendi._Earring off
https://www.bg-wiki.com/bg/Tangata_Manu which is a joke of a boss that doesn't really do anything scary and proccing it with Blizzard nukes/magic bursts seems to disable the scary status effects on it's harpy TP moves. I personally tanked it on DRK/SAM and duod it with a WHM + trusts. Strong to light skillchains, use darkness. Then pick up a Chatoyant Staff off the AH as well as a Tempered Cape, a sirona's ring and Ephedra Ring. You can also use your reforge AF1+1 pants for cure potency(BIS).
This should be enough gear to get you started. Don't listen to people who say you can't play X job, and need to be Y. Play what you like and what you want. RDM isn't the best job in the game but it's WORKABLE and PLAYABLE and if you put in the effort(get good at melee rdm!) it's a very useful job to have and is very helpful to have around. Play the strengths of RDM and know when to melee and when to /SCH backline.