Ranks in Warframe don't have the same meaning as levels in other games. They don't confer more damage or higher stats to weapons. Ranks do increase some stats and abilities on frames. Mods are the most important thing to progression. Enemies have levels, but these only give an indication of how difficult they may be to fight. Enemy levels cannot be directly compared to equipment ranks, and especially not to Mastery Rank.
Depends on what the source of the blood is.