yikes... old thread. not sure how this fandom goes about old threads, but if this is closed after this reply, then so be it - my bad for bumping it with this reply.
anyway, the dynamics of this vs battle are pretty wild. there's too much ambiguity bound to rama. obviously, nerfed kid rama would probably get slapped (restrictions in play, ofc), but prime is likely a different story, and more interesting to consider. as far as i know, there's been no real expansion on vishnu bhuja (other than his use of it in some animation update in f/go (correct me if i'm wrong), unless there's been some dedication to explaining its dynamics any further.
if we base the potency of the weapons with respect to his authority with increased divinity (nigh-prime, knowledge-unbound rama), then we have no idea how it would go, since we don't know how fate wants to interpret the lore behind the arsenal of vishnu bhuja. if we take the lore at face value, he slaps with the trishula (unless you'd like to restrict that for some reason), or even the sudarshana chakra, no diff. so, conceptually, he slaps, but interpretation-wise we have no idea. (additional note at bottom)
also, to whoever mentioned ea/enuma elish ripping apart space, i don't think that's the case, since material book iii mentioned its potency to be equal or slightly above that of excalibur (assuming equal mana supply). what makes ea so effective in the situations it's used in is its hax of "...the desire to remove all that is unjust and impure, and then returns to proper form," which is why it easily deals with reality marbles, and has increased potency against servants, if they are naturally bound by gaia.
- additional, somewhat related note: fate likes to be weird and consider vasavi shakti to be stronger than brahmastra, for some reason, and we don't know the full efficacy of fate's pashupata (e.g. heavily nerfed in e-pluribus-unum against demon god pillars). stating that pashupata is equal to vasavi shakti on arjuna's profile is purely headcanon, since it was never used in his backstory, and scales eons higher than vasavi shakti in the mahabharat. obviously, we're faced with ambiguity with respect to fate's interpretation, but it should be stated that its potency and dp are unknown, rather than assuming it's 6C of this fandom's tiering system. if you want, you could probably reasonably scale its dp with new knowledge of arjuna alter's heavily-implied shiva blessings, as universal, since such a jump isn't so far-fetched in f/go anymore, but to stay as true as possible, unknown would be a the best classification.