i'll combine this with the other request for actor au ivantill but

• actor au ivan is good with kid till because ivan plays well and keeps up with any hyperactive needy kid (and adjust to all his diff moods)
• actor till is good with kid ivan bc he’s quiet and does his own thing and kid ivan likes that so its like. parallel play
• all of the kid actors think that till is the coolest, followed by sua, then luka. no one thinks ivan is cool after they talk to him
• ivan has a great memory but he's very awkward with blocking and ends up practicing it or watching other dramas for inspiration, but till catches him one day and offers to block it with him (ivan says woof)
• ivan always posts behind the scenes on his ig (whether it's as soon as he takes it or later on after the drama is out) but with alien stage it's 100% all till in every behind the scenes
• luka is the most considerate to staff in terms of giving them snacks or trying to help out with work where he can (says it's in the name of efficiency but i think actor luka is just a nice guy. a deep oddball tho)
• the pipeline of "ivan you look cold take my blanket" to "sunbae let's share blankets!!" to cuddling on set fully
• ivan never gets leading roles until till puts in a good word for his acting skills; as an idol, he went through the whole "minor roles" to "sub male lead" phase and till got mad at the casting without realizing it (till voice no what do you MEAN xyz is ml over ivan?? does that make sense???? ivan's the most male lead material in the whole show no matter how you look at it????? bystander voice um till-nim why are you so mad..)
• ivan learns how to take care of staff on site by watching till (it is also very obvious to everyone who he learned it from. very endearing)
• ivan studies his script a ton because while he has a good memory, he isn't great with creating nuance or certain undertones in the lines and giving the lines the subtle emotion it needs, which is why he relies on the script's descriptions or asks the director (and later till) for clarification. so lovely and earnest
• till is the total opposite in the sense that his memory is pretty bad, but his sense for emoting and acting out the lines like it's his own life is unmatched. his script is also super marked up like ivan's but for opposite reasons
• till keeps every one of his scripts of his favorite roles for nostalgia... just to look back on the memories...
• the first time they're cast to play love interests (with a HAPPY ENDING) ivan texts luka like i can ask till sunbae to practice kissing with me right??? that's something actors can do???? and luka's like um i guess but didn't you do that for alien stage too... and ivan's like FUCK!
• ivan is a walking jungle gym for the kid actors. ivan's manager looks at them terrified IVAN REMEMBER YOU HAVE A CONCERT IN TWO DAYS...!!!!
• after alnst production finishes, ivan invites till to a concert and begs him to show up and till's like hmm yeah i guess if i have time i'll check it out (teasing) but then he kind of. becomes a fan. comes to ivan's concerts and shows unasked. the other fans are happy to see him and they give him a luka banner/fan and till accepts it thinking its funny. ivan sees till holding up luka merch and suddenly luka feels a chill down his back
• till professional ticketer btw it takes him some time to figure it out but he gets it quickly
• ivan does many stunts himself :D
• till does nearly no stunts because he's "old and my job isn't to do cool things it's to look cool and not break my back at 32 alright"

this was a lot but i felt like i had to give a lot for keeping this in my inbox for so long... i have a lot of thoughts about actor au it's just cooking... thank you sm for the ask!!