"I prefer IM, IM, Tan, Im, Tan, Tan or take the last Tan as first skill if you feel that you can't beat the arena for the blue armors"
What weapon do you use?
Whatever I feel like :p
If you look at the victorious AoB mortems in the Post Mortem forum for example:
http://forum.chaosforge.org/index.php?topic=504.0
http://forum.chaosforge.org/index.php?topic=452.0
http://forum.chaosforge.org/index.php?topic=422.0
http://forum.chaosforge.org/index.php?topic=471.0
Im+Tan are the skills of choice and in my case I also used it to beat AoLT challange on Hurt Me Plenty (http://forum.chaosforge.org/index.php?topic=474.0)
Im is the skill of choice for AoB because the LS gives + 6 armor, combined with a red armor that means -10 damage per attack
so it takes the monsteries quite a while to reduce you to 0 from 80 (with Im(3)). And since you don't need any weapons/ammo in AoB you'll be loaded with armors anyway.
For non AoB it's also very useful for the same reasons. When you wear an armor you already take less damage from attacks so the best thing you can do is increasing your health pool.
"Hellrunner is somewhat useful early on but quickly turns into a wasted skill"
Even with 2-barrelled shotgun \ Shottyman?
hm, the combination with shottyman makes it somewhat ok I guess, depends on how much movement costs opposed to reloading on the spot.
The fundamental problem with hellrunner is that it just increases evasion. If you wear a blue armor it reduces the average damage from a plasma shot from 4.5 to 2.5 (55%) so Hellrunner effectively gives you a 10% chance to dodge 2.5 damage while a level of Tan guarantees you a reduction from 2.5 to 1.5 (66%) and Im gives you 10 more health which translate into 4 more hits that you can take.
This is of course a simplified situation. Hard hitting attacks are different but since you'll wear armor anyway Im is the skill of coiche (as I stated above).
You do know that there is a minimum damage of 1? Cause in melee games after you'll get the spoily weapon of mass destruction, additional armor after wearable armor is most of the time useless, but Hellrunner lets you evade those points of damage completely AND will get you to enemies faster, where you will just massacre 'em.
Hellrunner(1) = 10% to evade 1 damage while Im(1) = 10 health = 10 more hits.
Hellrunner(2) also only evades 1 damage in that case but Im(2) means 20 more health which equals 20 more hits. That means you have to evade 20 attacks to equal Im which statistically means being attacked 100 times (100*0.20=20) which means the remaining 80 hits would be eough to kill you. Even if you are REALLY lucky and evade twice as much you'd still be dead after taking 60 damage.
So no, Hellrunner's evasion does not make any sense at all when fighting enemies with a low per attack damage.
also "wearable armor is most of the time useless" what the..? 6 armor from LS makes wearable armor useless when fighting cybie, AVs, barons etc?
Even lowly sergeants do an average of 12 damage only AA + LS combo can reduce that to 1
even Tan(3)+red armor only redcuses that to 5, so additional armor is NEVER useless whereas a red armor is enough to make chaingun/plasma attacks do minumum damage at which point Hellrunner becomes obsolete.
Hellrunner is also highly useful for evading those high damage ranged attacks completely (I had only 1 level of it, though evading while moving is already pretty high, but Cybie managed to hit me only twice in my AoM win). And for Shottyman, you will be evading much more attacks while moving, so it's much better to move than just sit still and reload if there are nasty monsters ready to fry your ass.
Depends sorely on luck. You yourself said that cybie managed to single-shot you from >50%. Statistically speaking Helrunner(2) means every 5th attack that would normally hit you (i.e. not evaded through coward/movement) is evaded by Hellrunner(2), so 4 attacks hit and fifth misses. 4 hits from a rocket launcher do an average 64 damage before armor and 3 do 48. So with a bit of bad luck 3 hits can kill you and Hellrunner(2) won't help at all unless you are really lucky, but I don't like to rely sorely on luck and Im(2) gives you 70 health, which is enough to survive 4 hits or even 6 with red armor.
Im is the only effective defensive skill when it comes to enemies with high per hit damage. And every sinlgle point of armor you gain though items/skills makes Im better while every point of armor makes Hellrunner worse because it means each evaded attack is "worth" less health.