Question about a Facebreaker Build
That depends entirely on what you want to do. Keep in mind facebreakers are the most gear dependant build in the game, and you Pandora Silver Gold Yellow Charm 174 will need sufficient funds to still be relevant lategame.
First things first: You can crit when unarmed, so get RT. No reason not to.
In any case, there a couple key uniques to any facebreaker build. One of them are the Facebreakers themselves, of course. Try to get some with 950% more unarmed damage, they should cost you 2chaos to 1gcp (Standard league).
Next up is Meginord Girdle. I think you can get them for 3GCP or something like that, maybe someone is selling cheaper I don really know though because I haven looked to buy one for roughly 4 months.
Those two are absolutely needed. Next up is the fact that you need to decide on if you want to go Life based, or CI.
For Life based, you can utilize the Bringer of Rain unique helmet, if you have the funds, as it adds a nice amount of physical damage.
If you want to go for the really high numbers though, you need to use the Abyssus unique helmet. The Abyssus has serveral downsides, a) it has no life or ES and b) you take increased physical damage. On the flipside the damage it adds is absolutely insane and makes to possible to progress to maps and far beyond if you Pandora Silver Gold Yellow Charm 174 can work around the weaknesses.
Next up is choice of skill. I suggest you pick one AoE skill from (Infernal Blow, Cyclone) and one Single Target from (Infernal Blow, Frenzy) or you just say FUCK IT and use (Dominating Blow) to pave the way for your fellowship.
Infernal Blow + Melee Splash has the interesting interaction of popping all monsters in the splash radius instantly, resulting in multiple explosion which in turn can cause even more monsters to die. The splash size and explosion size is increased via Inc AoE from the tree and/or from Quality Gems (both IB and MS quality adds AoE radius).
Cyclone I have never truly been interested in, so I can comment on its effectiveness. Although I cannot imagine what kind of skill bests one that instantly kills monsters in a certain radius with one hit, except an ability that does the same but in a wider radius (read: discharge).
Frenzy is extremely fun to use as well because the massive attack speed boost really makes your DPS skyrocket, however it isn as good for multitarget as IB and it makes your mana drain like crazy as well. I recommend IB for AoE and Frenzy for SingleTarget. Although IB does so much DPS you can mostly use it as SingleTarget as well.
Generally I would also recommend the Duelist start for any Facebreaker character because it has no wasted points, even when escaping the starting area. Starts from other classes tend to come to Duelist territory anyway to grab Master of the Arena. Also the %MeleePhysicalDamage nodes are really good for DPS.
Next up is the choice of CI vs Life. And here is where it get really interesting. For a Life build Pandora Silver Gold Yellow Charm 174 you need to take care to get huge amount of Life on all your equipment your quiver/shield, Helmet, Boots, both rings and Amulet. Couple that with the need to have high phys damage rolls on the jewellery as well and that you need to somehow cap your resistances, jewellery can get really really rare and thus very very expensive to get.
On the flip side, CI has it own slew of problems. Namely shock stacks, stun, freeze duration and the need to have high ES values on Chest/Helmet/Shield. Quiver is not really viable anymore, as are the two unique helmets if you value a high ES pool.
To combat the status effects you will need to carry the appropriate flasks all the time. Dream Fragment is pretty much out of the question due to aforementioned gearing difficulties. That leaves us with Alpha Howl (possible if you are prepared to give up a big part of your ES) or Wanderlust boots. Neither offer great resistances, but Wanderlust boots are cheaper to get and offer a bit of ES as well.
Taking Unwavering Stance is pretty much a must as well.
CI is not without it upsides, either. You can use Blood Rage for an incredible survivability boost, and Vaal Pact for even better survivability. You can use the Melee Damage on Full Life support which will further UP your damage a considerable amount. Roughly Pandora Silver Gold Yellow Charm 174 the same amount a Bringer of Rain would add to your damage. Also, ES on jewellery is a bonus but not required, somewhat making it easier to shop for jewellery. 300 ES helmet, 400 ES shield and 700 ES chest to feel really tanky. You will also need to be very high level to pull CI off because you need to travel all over the tree.
Also you will need a lot of RED sockets for the skill and support gems, which are hard to get on pure ES chests, making AR/ES hybrids a much more attractive choice > lower ES total.
I myself have started and leveled a few facebreakers over the time, the highest one is lvl Pandora Silver Gold Yellow Charm 174 72 and retired Pandora Murano Glass Bead 148 a CI Frenzy Facebreaker Ranger who I started way back. It worked out okish, offering 4k ES prepatch (using Alphas Howl) and 7k splash DPS with a non q Frenzy. The horrendus mana costs and still somewhat meager survivability made me stop playing her, though.
The facebreaker char I am currently working on is a Facebreaker Duelist, planning to go CI once I reach Tiffany Large Heart Tag Bracelet lvl 71 for my chest. Also planning on mostly forgoing defenses in lieu of MORE DAMAGE because Softcore, and switching out the ES helmet for Abyssus. I not sure how the combination of lower ES and higher damage taken will pan out, but with the absurd damage number that will produce and instant life leech I feel I should be safe enough. I have yet to get that high level though, and it might take a while because real life.
For reference, I am currently lvl 57 in A2 Merciless with decent FB gear and have 6.1k DPS on a 4L Infernal Blow with (IB, Melee Splash, Melee Phys Damage, Fire Pen). That is enough to 1shot every white and most blue mobs in A2 merciless (exceptions are Golem cause they tanky as fuck). I will try on the Abyssus at 60 just to see how much tooltip DPS I can get with Abyssus+MeleeDamageOnFullLife instead of Fire Pen, so I Tiffany Arrow Necklace know how much I will hit for later on.
Also, an afterthought, you can switch out the Meginords Girdle for a 24% Rustic Sash if you really need the survivability and don mind the harsh DPS drop. I would not do it unless I absolutely had to, though.
I chose Fire Pen because I don really need more damage against unresistant mobs at the moment, and Fire Pen helps a LOT against resistant mobs as the fire damage you do went up from 25% to 60%, essentially a 140% damage increase for that portion and an overall 70% damage increase. Worstcase scenario of unresistant mobs nets a 17% damage increase.
Added Fire is just subpar in my eyes, a nice touch if you get a 6L, but is only for tooltip DPS showoff not actual damage numbers. You will always do 139% of damage regardless of mob resists, and later on almost every mobs is ele resistant (the white mobs die anyway, regardless of gem choice). Fire Pen is better for those edge cases, and since IB Facebreaker is notoriously bad in Group Settings I assume you don have a dedicated curser with you.
I found I don need a mana leech gem by using Warlords Mark, which would free up your 5th slot.
Multistrike is gimmicky, I feel. I tried it and it was definitely nice and helps a lot with mana costs, but the more hits but less hard mechanic is something I try to avoid, to still be able to 1hit blow up groups of mobs. I don need to spread the damage around when I can just kill the whole group in 1 hit. If it get to the point where I can no longer do that I will revisit Multistrike. So far I could always kill whole groups simly through positioning and attacking the mob located in the middle of the pack.