Don't think Eiling is Colossus level strength with that serum which is what I'm assuming makes him the challenge in this. That said Nimrod can easily punk super strength and super durability character. It'll just be a matter of super focusing a laser through his skull while Eiling can't do much to Nimrod and even if he did the selfrepair on Nimrod is more effective than a lot of regenerators when you consider how durable he is making most damage minimal and gives him enough time to repair any damage and adapt to the attack while most characters try to whip up a similar attack in hopes of doing some more damage.
Eiling has no chance.