-Your items didnt match your build at all
-Choosing blood straight away instead of waiting till someones follows you past tower to finish you off.
-Leaving line in first minute when having a monk. It would heal u to full hp in the time you took to walk back and forward.
-Leaving shop without portal or pot to gank/pull someone towers. even when you had money for it
-late currency
-No shield till lvl 9 (thats why you died first time and thats why rook died little bit later)
-I cant understand why your rook and sedna were standing on mana flag whole game instead of hp flag
-Pen 1 at lvl 6, then full pen but no shield
-at 12,30 if you would shield rook he woudnt die. But you didnt have shield lol
-rook ported on full hp ub and oak and was tryin to fight them 2v1 and died before sedna moved from other side of map
About ur build:
I have no idea what was your plan there LOL. (lvl11: raise dead wand, sould power 1, surge of faith 2, shield 1, divine justice 1, full penitence).Item build is good for assasin oak except Scalemail - should be replaced either with Namroth ring or Groffin warplate. THere was no need stacking armor in this game since no one went full dps or or minion build. Extra mana or hp would be far more usefull here then armor stacking.
You shouldnt be mad at teamates. Past 15 minute there was no chance that you guys would recover from 8 kills and 3 war ranks missing.