Advanced Genetics - This would make for a lot of awesome combat using explosions, teleportation, etc. and the extra health and buffs would make for a hell of a game, although the mod itself requires a lot of machines, a lot of time, and generally is an uninteresting mod to advance in for such a short game.
Advanced Terrain Generation - I love this mod to bits, although feel that UHC isn't the place for it. It makes large mountains, continents, and in general the things you don't want in UHC. I feel that the environment for this sort of gameplay should be varied, flat, and have a lot going on to accommodate the mass of different things happening in the game. People don't want to dig up from bedrock after finding gold into a 200 block high mountain just to get out.
AOBD - This is such a small mod that I'm sure it doesn't harm anything, but is it even needed? I'm sure no-one will have massive automation systems in that need all of the dusts from here.
Applied Energistics - The majority of this mod will be useless and too late game, but the quartz grinder seems useful. Quartz tools not so much since there are a million and one better tools than these, but what else does this mod offer for such early game?
ARCHIMEDES' SHIPS - This could make for some very interesting gameplay in my opinion, I'd love to see it put to use for combat although the fact it's so glitchy at times isn't that great. I know the game's not about aesthetics, but no-one will have time to make it look good, will it even be fun just seeing massive blobs of blocks fly away to where no-one can reach?
ArmorStatus HUD - I use this mod myself and add it to all modpacks I use, it's an unobtrusive and useful little gem, and no doubt will be useful for combat too.
Ars Magica 2 - The progression in this is very steep to get anything terribly useful, but it would be awesome to see this put to use in combat. The fact that health and regeneration spells are early-game don't bode too well with me either.
Atomic Science - Forgive my ignorance, but what does this even offer for combat?
Balkon’s Weapon Mod - Superb choice. Early game, simple, and focussed on combat, even opening up different combat styles. This fits perfectly.
Better Storage - Backpacks are cool but there are a lot of other options for portable storage so this isn't unique enough to stay. Drinking helmets are an awesome idea for those short spouts of battle when you don't want to waste a whole golden apple or whatever, although potions are so rarely used in vanilla UHC and with the mass of other options in modded UHC I highly doubt this'd get used at all. Nothing else in the mod seems useful at all.
Bibliocraft - Aesthetic mod only, has no place here.
Bibliowoods - Biomes O Plenty - Aesthetic mod only, has no place here.
Bibliowoods - Highlands - Aesthetic mod only, has no place here.
Bibliowoods - Natura - Aesthetic mod only, has no place here.
Big Reactors - Only used for power generation and there are a ton of other options for powergen in this pack already.
Biomes O' Plenty - Varied terrain, this'd be more interesting than vanilla environments, but I think a lot of the more useless or overpowered biomes should be disabled (spawning in an apple orchard would be insane).
Blood Magic - This'd be very interesting with the fact the entire game is based around not healing. I saw mentioned earlier the argument of using mob farms, although as far as I'm aware you can only use that from tiers 2 or 3 higher, how would you progress early on? That being said, a lot of the tools and utilities offered by this (such as the air sigil for easy movement or phantom bridge sigil to get a height advantage on opponents while shielding you from below) would fit in perfectly.
Carpenter’s Blocks - Aesthetic mod only, has no place here.
Chisel - Aesthetic mod only, has no place here. Sure the spawn can be made out of these blocks, but why these? It's not like there aren't any other decorative blocks around.
Damage Indicators - Everyone's comparing modded UHC to Mindcrack's UHC, on that you can see people's health on the player list, so why not here? I admit that seeing it here on-demand would be a big change as you don't think to check other's health on the player list when you're in combat. This'd be a big change to combat, you'd know whether to charge towards someone if they have low health or keep pot-shotting them with arrows, and it'd be a different game entirely. Then again, with things like the thorns enchantments, Witchery poppets, secret rooms blocks and such, this could also be used to lure people as you can never know what they've got lined up or in their hotbar.
DartCraft
Deadly World - Too deadly when the combat is meant to be player-to-player.
Dungeon Pack - Dungeons are cool, dungeon loot is cool, just don't make them too difficult so that PvP won't happen, nor too easy so that the dungeon loot is overpowered.
Ender Storage - The crafting recipes for these things by default are too expensive to be worth it, although starting off with an ender pouch each would be awesome to put your team colours on to safely share things with your team.
EnderIO
Engineers Toolbox
Enhanced Portals - Teleporting is always cool, but it doesn't really fit here on such a small battlefield when you're going to be constantly moving anyway.
EVOC - Minor but useful.
Extra Cells - Too late-game to be useful.
Extra Utilities - The amount of RF generators this offers are great and will offer people a lot of different ways to get into powered things early on, not to mention unstable ingots making things like the ethereal sword and healing axe (more health regeneration options!) and the magnum torch (who likes worrying about mobs when caving anyway?) are all useful.
Flat Signs - Why? Such a small aesthetic change for a block no-one uses in UHC.
ForgeIRC - Why? You want to be talking to your teammates, not IRC.
Galaticraft - Yes, space battles would be awesome. No, they're not viable in short matches or offer anything other than higher jumping and slow-time arrows (and be honest, who will even bother using boring old arrows with the new weapons available?).
Gascraft - I'm not too familiar with this mod myself, but the gases you can use as weapons here don't seem any more effective than placing down a bucket of lava 3 blocks infront of you. What's the fun in that?
Hardcore Ender Expansion - The End is far too end-game (get it? haha) for such a short round. One look at the Ender Dragon and that team's dead.
Harvestcraft - Why? People will be running around and doing things other than farming.
Hat Stand - Why? No-one will be staying in one place to put down a hat stand.
Hats - Why? Offers nothing useful or helpful, the biggest use I could see in this is each team having their own hat to wear, but here are a ton of better alternatives than that as far as I'm concerned.
Highlands - An awesome biome mod so I can't complain, but for what I feel should be a small and more tightly focussed pack, I fail to see the need for both this and Biomes O Plenty in the same pack.
ICBM
Infernal Mobs
Infinity Bows
Inventory Tweaks
Jabba
Journey Map
Lava Monsters
Magical Crops
Mariculture
Mekanism
MFFS
Minefactory Reloaded
Modular Power Suit
Modular Power Suits Addons
Natura
NEI
NEI Addons
NEI Plugins
Nether Ores - Another reason to go to the nether is always good, especially since the nether is more dangerous now.
Not Enough Keys - Small clientside mod, useful.
ObsidiPlates - Useful for houses, houses that I imagine people won't really have in UHC. Regardless, I see it as being useful for blocking off cave homes and such.
Open Components - v
Open Computers - I can't imagine anyone will need a programmed computer system to do anything for them in such a short game focussed around combat.
OpenBlocks - Hang gliders are cool for traversing terrain,
Pam's Clay Spawn - Never had a problem finding clay myself, not sure if this is needed. Forcing people to go look around rivers is a nice way to force combat.
Portal Gun
Project:Red - Sickles are cool for getting apples easily, gem tools may be nice early on, I can imagine dye trees may be useful if people can't for example find a desert and they need cactus green for a recipe.
Railcraft
Railcraft Dusts - Out of every mod in the pack, Railcraft seems like the least likely one that people will be ore processing with.
Redstone Arsenal
Remote IO - Why? This could be cool for traps and such, but you'd have to be there and there are a ton of other things available for traps.
Resonant Induction - I'm not personally familiar with this mod, but the progression seems steep and I don't see any useful equipment it offers that other mods don't.
Roguelike Dungeons - What I've said about the other dungeon mods. Nice, good for loot, but balance them well.
ServerTools
SortFix
Special Mobs
Steve's Factory Manager - What use will people even have of this when they're just trying to survive?
Thaumcraft 4 - With the free cheated Thauminomicon, this seems like a must-have, even if infusing may be a bit complicated for such a short game.
Thaumcraft Mob Aspects - There aren't many extra mobs added to the game and even so they don't really offer aspects you can easily get other ways, in the idea of keeping the pack small I'd personally keep this out.
Thaumic Reliquary - Forces people into ThaumCraft unnecessarily. ThaumCraft already offers enough of its own unique equipment, I'd leave this out to keep gameplay diverse and allow more people to use Xeno's Reliquary.
Thaumic Tinkerer - With Thaumcraft, definitely yes.
Thaumic Tinkerer - KAMI - May be extremely overpowered, once someone gets these tools and armour the game would pretty much be set.
Thermal Expansion - Imagine using florbs to fight, it'd be amazing! Offers everything from ore processing to portable storage to tools and weapons, and is easy to get into for the most part.
Tinkers' Construct - Obviously useful, offers a diverse amount of tools, weapons, easy enchantments, etc. Ore doubling if people build a smeltery is a plus, breaking down oak leaves easier with a scythe is useful, rapiers ignoring armour would be far too overpowered though. Bow combat with this would be very interesting.
Tinkers' Mechworks - Awesome mod for building bases, but that's not what'll be happening here.
Translocators - No-one will be building sorting systems or automated things like this, the only use I see is the portable crafting grid which is useless when there's the DartCraft clipboard as an option.
Twilight Forest - Offers nothing except another dimension to run around in. Sure some weapons and armour can be cool, but not better than anything else available, and no-one will be fighting the bosses.
Utility Mobs - Set up a ton of mobs to attack your enemies, game won. Not sure if these utility mobs will be useful when no-one has a base and the entire game is PvP anyway.
W.A.I.L.A - Bare in mind this has the same functionality as Damage Indicators in that you get to see other player's amount of hearts. Also if Secret Rooms is installed, the appropriate settings would be needed.
Weather
Witchery
WRCBE
Xenos' Reliquary - Adds a weapon, some cool potions, useful utilities for traversing the nether and such, this could fit in quite well.
Zombie Awareness - Makes mobs too overpowered when the pack should be focussed towards PvP.
