Based on OP stats, he is level 128.
His hit rate would be, if not counting any hit gear, and including his stat buffs, 380.
Hit rate = (175 + base level + dex + [luk/3])
As others have posted, angra mantis needs 499 hit for 100% chance hit.
For every 1 hit missing from 499, is 1% chance lost.
So 498 hit would equal 99% hit rate, 497 hit would equal 98% hit rate.
Angra mantis (499) minus You (380) equals 119 hit missing for 100%.
Since there is a floor of 5% hit rate. You current only have a 5% chance to attack those angra mantis.
Stat wise you went a little too heavy and too early on str. You should have invested more into vit/dex. Personally, i would get 90 str(HBP/RT bonuses) then stop, and pumped vit to 90+, dex to 70 and maybe luck to 30.
To make up that 119 difference, I would suggest, FS enchanted gear, dual FS mummy drill katar, and RT.
dual FS mummy drill katar = 60 hit
dual RT = 20 hit
WCP = 5 hit
triple FS FAW = 15 hit
triple FS nab = 6 to 10+ hit
ancient shadow armor = 10 hit (20 hit if +7)
This set up would net you 116 to 130 hit, which would be enough to attack angra mantis.
when i just started high ti, as a low level gx solo, i used drill katar on high hit mobs like parus, etc, until i was high enuff level to smack them around without it. Damage is doable, as long as you use convertors and edp.