Astral blade passive translation is wrong
It says "Using temperance to buff spells makes the effect much more potent" What it actually does is give you +10 spell power extra no matter what needle you use. If you use magic bone needle which increases spell power by +10 now it's +20 total. However you are better off using any other needle as you get half of that effect anyway. I started using arcane needle as the damage from the buff still scales with magic stat.
Damage test with +5 astral blade with 30 base spell power and infernal flames spell (no burn) it's:
No temper 130 spell power : 380 Magic needle 150 spell power : 438 Any other needle 140 spell power : 409
Every 10 spell power is 29 more damage for this spell which is not even 10% damage while the arcane needle literally doubles my melee damage at 47 magic while still giving me 29 spell damage instead of 58.