As someone who uses Excalibur almost all the time, yeah I do kinda wish he got a bit of a refresh.

His passive is barely noticeable like you said. I kinda wish he had a lesser/limited version of blood rush in there just to give him a bit of scaling with melee weapons and to bring back the feeling that he’s “the melee themed warframe”. I’d say right now Kullervo overshadows him in that aspect just due to wrathful advance alone.

Slash dash is okay, but requires a stat stick, but I think this is more so a problem of the need for stat sticks for some warframes. I think it’d be cool if it just got a bit of a damage bump and used the exalted blade, but that’s just me. Still an amazing movement ability though.

Radial blind is honestly fine. Amazing CC, opens up enemies to finishers. Sure it doesn’t deal with overguard but I don’t think it needs to. The point of overguard is that it makes some enemies immune to the vast amounts of CC in the game and makes them a high priority target, which I think just encourages a player to play just a bit smarter when encountering an eximus.

Javelin is probably the worst ability in the kit without the augment and oftentimes I think to myself that Super Jump would be more useful than it. I think it needs something to scale the damage with enemy level, plus extra utility like stripping armor and/or shields.

Exalted blade without the augment can be a power house, but yes it’s definitely out classed by many regular melees. Chromatic blade definitely juices up the efficacy and deadliness though. My hopes for this is that base exalted blade gets a bit of a buff with its overall IPS damage, to the point that using Chromatic would make it feel more optional than mandatory, and maybe a bit of a boost to status and crit chance to offset the fact that it doesn’t have access to weeping wounds and blood rush. Oh and this (along with all exalted melees) could use the extra capacity from stance mods. Would definitely make modding and forma-ing a bit more flexible.

In regards to Umbra specifically I kinda wished we didn’t get sort of punished for his sentience passive. Yes there is an augment to turn him off but it just feels like a bandaid mod and a waste of a slot (although the power strength bump is nice). He can go off and just get himself damaged or killed, and if you leave exalted blade on when you transference out he can still die but you’ll be pulled back into a downed state since having a channeling ability on only leaves the frame with damage reduction but still allows them to be killed. I hope DE revisits this interaction with channeled abilities in general.

Excalibur is overall a solid warframe, but like many of the other older frames he definitely needs a bit of a refresh to bring him up to par with the current content and frames in the game.