Coliseum is still hovering around "not actually better reward for the time spent than just playing AI", particularly if you end up failing either duel or if you get unlucky with champs. IIRC you need to complete all events successfully in about 8-10 minutes to match the ouei range of most grinding decks/targets, and if you fail DG you have to have finished everything in 3-4 min to break even.
Rather than just bumping rewards again, let's add a streak bonus for playing it X days in a row.
I'd say the streak bonus should kick in as soon as you complete any single event, so it's available to everyone and unmissable (assuming you play). Interface-wise, it can just work like the bonus nymph for completing all events.
As for actual rewards, what I would like most is if it were possible to do free packs that weren't account-bound. If that is too complicated for some reason, just the liquidated gold is fine (and might as well round it if we go that direction). Here's what I'm thinking:
First day: one bronze pack (or 15g)
Second day: one silver pack (or 25g)
Third day: one bronze pack plus one silver pack (or 40g)
Fourth day: two silver packs (or 50g)
Fifth day: one gold pack (or 75g)
Sixth day: one gold pack plus one silver pack (or 100g)
Seventh day: one platinum pack plus one silver pack (or 125g)
Eighth day: one platinum pack plus one gold pack (or 175g)
Ninth day: two platinum packs (or 200g)
Tenth day: one nymph pack (or 250g)
After day 10, reset to zero.
For reference, the ten-day bonus (nymph) is only 250g, which is a minute and a half of top tier grinding. This isn't going to meaningfully affect the economy for people who grind a lot (me) but is going to be very helpful for people just starting out, and makes coliseum a lot more attractive over just loading up monodeath and smacking the a1.
edit: see next post for updated reward proposal