If another effect (or effects) modifies how much damage a creature you control that entered this turn would deal (for example, by preventing some of that damage), the player being dealt damage or the controller of the permanent being dealt damage chooses the order in which any such effects, including the effect of Neriv's last ability, apply
Great, and you'll keep it
The same is true for the colors of the spell, the colors of a split card are both colors everywhere EXCEPT on the stack when being cast, where only the cast part(s) colors are used
(2018-06-08) If a creatures power is less than 0 when its doubled, instead that creature gets -X/-0, where X is how much less than 0 its power is
Biogenic Upgrade | Illustration by Tomasz Jedruszek Simply put, counter doublers are cards that let you double the number of counters already on a permanent