I feel like judging power and effectiveness on an opponent that basically renders it near impossible for him to have displayed those traits in the first place is slightly unfair... but I'll give it a go with my own ranking.
I'll go with more general categories though; (Each out of 5)
Combat Strength
Decision Making
Adaptability
Field Effectiveness
Combat Strength - 2/5
Shen's already made a pretty good evaluation of this one in his Strength, Effectiveness and Utility categories. You'd really faced a rather troublesome opponent and for most of the fight, you'd spent it being somewhat defensive and suppressed. Just judging based on the outcome of the fight Yasu came out far worse for wear. Given how badly Yasu actually fared against an opponent that countered him then I can't give you much in this category. However, decisive action was taken to maximize your jutsu and that definitely brought you up, albeit at the cost of points elsewhere.
Final Evaluation; 'Didn't get a chance to see much, decent at engaging in blitz battles.'
Decision Making - 2/5
Decisions were made, and as I'd said before I'd thought some of his actions were borderline suicidal. Nevertheless, Yasu was a ruthless ninja who could sacrifice on the field to open up an opportunity to get his opponent takes damage. A pyrrhic victory but a victory none the less. However, it must be said that you chose to prioritize winning the 'battle' over the war. While dealing damage is all good and all, tearing holes through your hand for the sake of barely getting a shot at your enemy, although a gutsy strategy, basically sealed your defeat.
Note that is was in no way necessary to have charged up to Zaku in a straight line and trade attacks blow for blow in a Warrior vs Mage situation. Clearly, the mage won by dealing enough damage to the warrior that despite having achieved his goal of getting into closer range he was far too beaten to actually do anything. Will attribute it to the whole Zaku beat up Tomiko situation.
Final Evaluation; 'Decisive battler but also takes unnecessary risks and lets his emotions get the better of him.'
Adaptability - 2.5/5
Neutralization attacks were good, but what else can I say? Facing an opponent who'd had the advantage to begin with, you'd focused on defending yourself from that advantage. While that was a good choice you went a bit too far (in my own opinion) and 'tunnel-visioned' yourself. You completely neglected to take advantage of your environment to, for example, hide behind one of those glaciers.
Final Evaluation; 'Adapted to his opponent but neglected everything else.'
Field Effectiveness - 3/5
If Yasu were to be promoted...well if this hadn't been an exam he'd already be a corpse. However, displaying such a level of drive to accomplish the mission makes you an almost excellent shinobi (The excellent shinobi come back alive...) and the village could stand at ease knowing Yasu would complete the mission even at the cost of his life.
Final Evaluation; 'Dedication to the mission that surpasses the average Shinobi, however, if you end up dying on the first mission it'd really be a problem.'
Overall Evaluation
An excellent shinobi, no doubt, but is maybe a bit too eager to accomplish his tasks. Fatal Flaw? Probably recklessness and excessive risks.
9.5/20