Probably too powerful.
But yeah. The biggest problem with Fel's Wrath is his lack of an Elite Pilot Talent. Interceptors are so dependent on not getting hit in the first place that no amount of damage capacity increases or 'cheat death' abilities really substitute for more actions or other ways to modify defence dice.
Having him stay alive for another turn by adding 'next' would make him more tempting - I still think I'd prefer a Saber or Royal Guard Pilot for the same price, but he's be a much more interesting option, because your opponent will always prefer to fire at pilots who actually die when they kill them...
I've never been convinced that his ability fits. His job is to watch the baron's back, and we know he was "told to stay back and allow Fel room to maneuver" - I'd be half tempted to make his ability a sort of 'reverse lone wolf', such that as long as he's on the board but isn't within range 1-2 of a ship, said ship gains some sort of bonus.
25-ish points is not an unreasonable price to pay for a force multiplier ship that improves an already good ace pilot (see fleet officer shuttles), but it's a bit too much for a guy who is basically just a PS5 grunt interceptor.
You are right, Fels Wrath ability don't make him a wingman. A reverse Lone Wulf would be interesting as well. But without PTL Fels Wrath would have trouble staying in R1 of Soontir anyways.
I also thought about an ability that only works if Soontir is in play as well, like If Soontir gets killed, Fels Wrath goes into a RAGE: attack value rises by 1 or gets a free focus tokan every round ... but in the end I settled with the ides in the OP. Its just so easy and effective as well.