My character is the “main character”.

My friend, (ranger/rogue) acknowledges and is okay with the statement that my character (warlock/paladin) is the main character. So much so, that he was the very person to suggest it. Here’s the thing, in terms of story development thus far, I have had a subclass change session built into the story, this was at level four warlock, fiend-celestial. The level after, I had a brief dialogue involving my backstory. The very next plot point that happened in regard to my character is all the way at level seven, (our current level) during a timeskip, being a training arc for one of my Paladin levels. In terms of items, which matters considerably less, I have gotten a very lackluster amount, being a cloak giving guidance as a cantrip in my spell list, and the rod of the pactkeeper (ironic, but anyway).

In terms of his character, we had a session revolved around hunting a drider, (he is a follower of a god who combats Lolth, as well as dragons) at level four, a heist involving a Drow relic, at level five, a series of dragons from levels 3-5, a session at sixth level dedicated to finding his rogue master, at seventh level, right after the timeskip we fought a chromatic dragon, in order to introduce his once-per-combat lance form/ability where he uses an action to teleport fifty feet up, then his action, bonus action, reaction, movement, and free action to pierce his enemy for 4d10 piercing damage plus his dexterity modifier. In terms of his magic items, the lance, at the current level, the armor accompanied with the lance/form, one magical shortsword and one magical scimitar (+1 each), a collapsing rapier (mainly flavor, with certain stealth implications), and a ring removing the need for both reloading and arrows.

He constantly complains about feeling replaced and as if I am stealing his job as being a mixed combat fighter, when I have had pact of the blade since I got the choice, therefore making me a mixed fighter with Eldritch blast and my spear. My explanation is that my class composition is just a stronger combo currently. Thoughts? How can I talk to him about it?

Note: to prevent any further confusion, I mean a change of subclasses from fiend to celestial, not a combination between the two.