One thing you have to know about Captain L is his execution is on point. He's mastered the QAL from dthrow and I've never seen him miss an opportunity after a footstool to QAL. He recently beat alphicans in pools and has taken a game off Felix. Shaya even said he felt he was the next best Pikachu next to Esam having played all the other Pikachus on his trip to NA.
That particular desync is my favourite desync and is probably the one I use most. It's initiated by dashing away so it's safe and puts me in an extremely good position. If you watch Kakera here, he uses this desync to approach Esam every time he is on the ground.
How most Ice Climbers lose this match up is by dashing towards Pikachu and shielding and getting bthrowed, but using this desync there is very little risk. I've only seen 4 ICs players use this desync, but I'd say me and Kakera are the ones who use it the most. Desynced Ice blocks completely shut down Pikachu on the ground.
My most recent game with Captain L Keep in mind with Apex we will be able to strike BF and SV, forcing yout to either Lylat, Yoshi's, or FD which are all incredibly good for ICs in this MU. You can see a lot more grounded play. Notice that when I do get grabbed a don't drop my shield as a means to shield any incoming pummels and I can punish the bthrow with a dash attack. Kakera did this as well when Esam was near the ledge and got a free grab out of it. Also I wasn't dashing as much and approached by walking, allowing me to react to dash grabs or initiate desyncs. During the 2nd half of the game I start to use the 2 dash desync a lot more.
I admit I made a mistake, the video I was thinking of is DEHF vs Brick. I searched for videos of Z playing a known ICs main in tournament and I couldn't find any. All I could find was him playing Fow's ICs in friendlies (fow was winning) There have been few instances where an ICs main played a Pikachu main at high level. Kprime lost to Pwii's ICs. I've probably played this MU more than anybody, offline and in tournament. The RPS game in this MU is so heavily skewed in his favour it's a wonder it isn't already +2. We dominate on the ground, we dominate in the air. It's much harder for him to separate us than for us to get a grab. Even if he manages to separate us it doesn't mean death as we can save Nana or we still have Sopo.