Diablo 3 fandom seasons wiki page has a great summary on all previous seasonal rewards:
https://diablo.fandom.com/wiki/Season (can’t link normally)
Now rewards from seasons 5-16 are on rotation so that everyone can eventually get them, but this doesn’t apply to S1-4 rewards or new S17+ guardian rewards added on top of rotated S5-16 ones (new guardian-only portraits and pets). And S4 is weird: it could be added to rotation, but somehow the rotation restarted from S5 (=S17), and S4 got excluded (why?).
Anyway, my proposal is to allow obtaining missed rewards from previous seasons by awarding single missed season rewards for reaching guardian in subsequent seasons, not including those which are on rotation.
That is, if I complete S24 to guardian, I would get all S24 guardian exclusive rewards, all S12 rewards (because S12=S24 in the current rotation), plus S19 guardian exclusive rewards if I missed S19 previously.
In summary:
Grant one missing set of rewards for achieving guardian in subsequent seasons.
Include S1-3 rewards into this selection (S1 and S2 could probably be given now for obtaining 100 and 800 paragon respectively).
Add forgotten S4 to rotation.
This way all missed rewards could be eventually recollected.
I play seasons mostly only for collecting unique vanity rewards, and I’m definitely not alone like that. Perhaps more people would return for seasonal content if this system is implemented.
Which season was the one with the Frost Pitbull? I think S4. That was the first season I ever played, and started it in its last week. I don’t recall seeing that pet ever again in subsequent seasons.
I also got the S3 pennant even though I never played it.
Exclusive banner shapes, patterns, accents, and sigils (one for each S1 and S2).
I still use S2 banner that I earned back then. Suits my theme since I play only seasons anyway.
Might actually be an intentional but undocumented way to recoup S3 rewards. I would give S3 rewards for reaching level 70 solo on hardcore. So my proposed summary for S1-4 rewards:
Conqueror transmogs for leveling up to 70 during season (any game mode), as we already have right now.
Grant S1 rewards for reaching paragon 100 during season (any mode).
S2 rewards for reaching paragon 800 in season (any mode).
S3 rewards for reaching level 70 on HC in season solo in a single marathon run (to prevent powerleveling).
S4 simply added to rotation.
I think it’s a nice way to reuse these.
We got only necro. These should have been attached to class achievements, I guess. But for some weird reason they aren’t. Reach GR100 with every class set? Just imagining a potential way they could be earned, now that we have separate leaderboards for each class set.