In my opinion Corvus can quickly become useless in a fight after his charges get finished and will no longer have his Dmg nor his immunities to bleed, shock and coldsnap. Medusa on the other hand is really good for some of those long fights where the every enemy has at least 77K health (Act 5, Uncollected, RTTL, ROL,LOL) and can be even be an MVP in AW, but at the end of the day this is a game so if love playing with Emma Frost or even korg then Rank them up instead.
Lots of good choices there and at the end of the day the champ you rank up should be the one you will play the most and best fills in your needs, whatever those are. But without more information, I'd probably go AA. In my opinion he has one of the best track records against tough bosses. If it bleeds AA can kill it, and it it bleeds and is vulnerable to poison AA is usually one of the top choices to kill it. A significant percentage of the content out there is not bleed immune, not poison immune, and not stun immune, and these things are basically AA-fodder.
Archangel will always have use, but his utility has been affected somewhat since the meta has been catered to counter Blade (and bleed). I would personally go with Corvus.
5.3 gave me trouble for a long time but i ended up solving the problem by putting 4* r2 Blackbolt and Karnak for the synergies. The 25% attack at the start of each fight gives you back a good amount of attack so you dont need to worry about the class
Thank you all for the awesome answers! I think I am gonna go with the votes and rank up archangel. I have 4 more tier 2 alphas and will decide between corvus and medusa as soon as I get more tier 4 catalysts. Most likely to rank up medusa based on your comments.
Comments
I would rather do a Sabretooth if you had him because he can nullify the -50% attack with some passive furies, but from this: AA.
AA close second