What's the strongest, most unfair AI for giant endless battles?

I love to play co op vs AI battles but I find they always run out of steam. For example the last game I played was a 2v6 vs extreme AI (90 minute treaty on Team Islands) and after their fleet was defeated by ours + a billion towers they just gave up on fighting water battles. Then we landed, had an epic battle trying to get a foothold to build a forward base, eventually built it, then after suiciding hundreds of monks into our castle they just gave up and all 6 AIs had no more resources to farm, didn't trade, and just gave up and rolled over.

I don't care if it cheats for infinite resources, what's an AI that will just spam units forever and never give up?

I loved Resonance Bot and BruteForce AI from AoE2HD but I don't believe they exist in DE.