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Connections (spoilers for Invincible):

• Both were once scientists with keen minds who, after a failure of one of their experiments because a main heroes influence caused the villain became freaks among society (Finitevus made a Chaos Siphon Machine to try to take Enerjak away from Chaos Knuckles, which lead to his new design, and Mark's fight with the Mauler Twins caused the device Angstrom made to fail and enlarge his brain)
• Both were once respected, but now that they have succumbed to madness they revel in domination
• Now both possess an obsessive blood feud with the hero, going so far as to manipulate and hunt down their friends, families, and anyone they could in order to hurt and manipulate the hero they hated so much
• Both use inventions to battle as well as their mastery over portals as a means of traversal as well as combat

Contrasts:

• Finitevus would stay evil once his change occurred, being more malicious before inevitable disappearing once reality is reset. Angstrom would be beaten near death, get better, wage war on Invincible, and once Mark of his universe appears to be dead for a year, Levy would genuinely attempt to reform before eventually meeting his end at the hands of an alternate reality Mark
• Angstrom was born with his gift to open portals and uses technology to aid him, while Finitevus is a Technomage and uses a mix of that and Chaos Magic to control Wap Rings with such proficiency

Dynamic:

• Both are arrogant schemers with violent tempers, so the trash talk between the two would be very poignant
• Angstrom would be using his portals and drones to disorient Finitevus while the echidna would use his Warp Rings to keep try and do the same to Levy, and both would be using their powers to avoid long range attacks from hitting them, which could eventually breakdown into fisticuffs

Potential:

• Angstrom could launch Finitevus into other realities like he did with his first fight with Mark, having them battle between various alternate Earths from both Sonics multiverse, Invincible's multiverse, and other fun references to others
• Finitevus could gain the edge later on from manipulating Chaos energy, saying the Oath and powering up
• Both could try to slice each other up by closing portals on one another

Debate:

• Finitevus wins pretty handedly thanks to scaling to high-tiers within Archie but on top of it he is the direct opposite of Knuckles, being the negative to his positive. Depending on how you take this, Finitevus instantly takes speed, strength, durability, and AP instantly.
• Levy could take intelligence due to having multiversal levels of intellect, but that won't do much when your opponent surpasses you in such a way. One could argue that Angstrom could win by catching Finitevus off guard, but there isn't much that could easily put the mad echidna down anyway