I really like that TV man

Susie: Starting with de obvious, since the game spells it for us at the end of his battle. They both share the fact that they feel unwanted and because of that end up making decisions that drives people further away from them.

At their core they are both very sweet and caring, but due to their insecurities and fears end up in the role of bad guy/girl, and only when they are shown kindness by others, shown that they are worthy of love as much of anyone else, that there is hope for them, they let their defenses down and show just how much they care for others.

Kris: This is difficult to say cos we don´t really know much about them, but both Kris and Tenna find themselfs in a similar situation.

Kris has a deal with the knight, a deal that in ch4 looks like they regret/ are having second guesses and are being coerce to continue by someone they care about (probably Carol).

Tenna had a deal with the knight, they show regret about their actions during ch3 and based on the "you aren´t going to unplug me again" seem that was coerce by someone he cares about (in this case kris)

Also, they are physically different to people around them, with Kris being the only human in town and tenna being in a different artstyle and taller than averague.

Also also, this is just my interpretation but I think that a lot of tenna´s feeling around the divorce may be proyections of kris´s feelings, since darkworlds reflects the will of their creators.

Ralsei: In short they both share the feeling that they are only valuable as long as they are useful and can fullfily their purpose, that on their own they don´t have value.

They have a little difference in that tenna is willing to fight to prove he is useful and beg to be allowed to live, while ralsei is clearly afraid, but has accepted it as reality and doesn´t try to fight it, we see this clearly in realsei´s encoraging words to tenna post boss fight, where he basically calls tenna selfish for begging to live (0 hate for the poor boy, he was trying his best to comfort tenna).

Noelle: Surprisingly they got a lot of stuff in common:

The biggest one to me is their connection to spamton, since both were given a pipis by him in the past, showing a level of care towards them, but in the present spamton seems to not care much about them getting hurt, ie the whole weirdroute and cathode screens into cathode screams/ the businnesman that died at the now of the story.

They both have a connection to the holidays, noelle surname is literally holiday and her house is chrismas themed and tenna whole talk about how he misses the family is centered around the holidays and he dies next to a chrismas tree. (also this is probably a coincidence but TV in windings is a snowflake and a cross).

they both have been hurt by kris, but still cherish their bond, as mention before, there is a big chance that tenna was threaten by kris but he nevers tells this to anyone and still shows that he cares about kris (even if he is a little afraid of them) and for noelle is very obvious kris pushing her away hurt her, but she still is really kind and willing to help them and in WR she is constantly justifing "them"

If you belive tenna did the boards, them both seem to be into moding stuff.

They are both really nostalgic and constatly mention things that happen when kris was younger.

Both of their arcs start with the help of susie.

And finally they are one of the few characters that notice something is wrong with kris.

Dremmur family: oh boy oh boy the dremmurs

Starting with toriel, they both share a similar nostalgia about kris and asriel childhood, toriel literally has a "kris remember when..." next to the tv in ch1, that is very similar on how tenna speaks throught ch3, both show a bit of aprehension about the kids growing up and both noticed that something is wrong with kris and try their best to help even if they are missing the whole picture.

In asgore case based on his UT counterpart, cos we haven´t seen a lot about him in DR, both deal with the guilt of taking a impulsive decision in the heat of the moment and regretting it a lot later, in tenna´s case the contract with spamton and going after the phone and in Asgore´s case the whole war against humans.

Asriel is a mistery to us at the moment, but tenna has some similitudes to omega flowey:

-Both angry tenna and his star attacks have the same smile as OF.

-The realistic depiction of tenna at the begining of board 2 is the same used for OF.

-In concept art OF had the antennas in the middle and the tv was purple.

-Tenna´s rimshot attack is really similar to an OF attack.

Spamton: Tbh to me they are more opposites than mirrors (and I may do a post about it) but they still have similarities in that they both spend their time after parting ways really isolated, spamton for obvious reasons and tenna shows this in "I been all alone" and both are really persevering.