Some more thoughts about the deck:
- Growth Spiral seems overrated. It's a 4-of in all the deck lists I've seen, but although it's good early, it quickly becomes an expensive cycling instant later ... you might not even have another land to play on the same turn. I see you're not running any at all. Do you miss them?
- Shock might actually be better than Shivan Fire. It can kill planeswalkers (especially Teferi & Vivien) after they tick down. I don't think I've kicked Shivan Fire yet.
- I *really* want to run 3x Search for Azcanta. It's a proactive play for 2 mana, and Azcanta the Sunken Ruin + Wilderness Reclamation is absurd. I think four copies is closer to correct than two.
- I've not tried Ral. I see you say he's effective against resolved fatties, but there aren't that many fatties that he can kill which the other removal can't (Lyra I guess; there're few other 4+ toughness creatures). You can also kill resolved fatties with Explosion.
- Hard to imagine not running Opt. They're still cantrips that filter for the parts you need & help flip Search. I do board them out but only because I easily run out of things to cut.
- Sideboarding with the deck is hard. It's not easy to tell what cards to cut because they're all there for a reason. Often I find I'm just cutting the few bad cards for more creatures, and diversifying my creature suite. I see you're not running Rekindling Phoenix which I suspect is a mistake; that card demands special answers and is quite cheap too.
- I currently have some Pelakka Wurms in my sideboard for the monored matchup, but this could be completely wrong because they're 7 mana cards that'll be hard to reach without Growth Spiral. Maybe Fountain of Renewal?
- Hard to see Dire Fleet Daredevil as worth it. You don't need more value.
Some cards I definitely want in sideboard:
- At least two Negate for counterspell wars. Actually considering Spell Pierce too. Many of the ways other decks use to fight you are non-creature spells.
- One (more) Niv-Mizzet for counterspell matchups
- 2 Biogenic Ooze to diversify creature threats
- 2 Rekindling Phoenix for the same reason
- 4 Fiery Cannonade. Of course some are already mainboard; the remaining copies should be here.
- 3 Shivan Fire / Shock, depending on how many are in the mainboard.
- up to 3 Crushing Canopy - for Wilderness Reclamation, Cindervines, monoblue, anything with Thief of Sanity
- Something for the monored matchup
- Potentially Entrancing Melody for white aggro
It's definitely the case though that I run out of cards to board out sometimes, e.g. against white aggro, I want the cheap removal, cheap sweepers, Phoenix, and possibly Ooze. I can take out Niv-Mizzet and Sinister Sabotage, maybe a copy of Expansion//Explosion, but beyond that there're no more bad cards, which is why I'm often boarding out Opt.
1. On the Growth Spirals, I think they are very good but I don´t think they are very good in this deck... I rather have 1 Lavacoil in hand than 1 Growth Spiral.
2. The deck initially had shocks, for the exact reason you say... I can see my self returning to shocks over Shivan Fire but then again you might want to go for Lighting strikes so then you have 2-3-4 damage burn spells, I will test the Strikes but I see your point and kinda agree.
3. On the Azcanta, I think you are probably right... I most times boarded out against aggro, but I have one more copy on the SB I think 3 copies might be the right number against control but on the main deck 2 seems enough IMO... this could be tested.
4. Ral is a soft spot... I love that guy but he might get the axe in the long run, most big threats are dealt with EXP/EXP but I really like resolving one and defending him with counters... by the time Niv arrives all the removal is used.
5. Opt I have not test it... I cant find room for it, what will you swap?
6. Phoenix is interesting for sure... I run 2 Ooze on the SB to make use of the floating mana... one activation on end step and you have 9 P/T on the field on 3 bodies that is huge and can end the game on the spot... this is very fun to run against the Nexus decks that remove their Root Snares.
Have you tested the Phoenix?
7. Pelakka seems like an odd choice... you cant really make use of the Reclamation mana don´t think is a good idea.
8. Dare Devil is a house against control... Esper and Dimir eats a bit of their own medicine.. like when they cast Ego.. and you then cast that on them or kill their Teferi with their
mortifyContempt, Thought Erasure... I love it and would not change it at all.
Against WW I take out Sabotage and Azcanta, I never touch EXP, Niv, Reclamation and always leave at least 2 Syncopate, if you know what your opponent will be running then you can go BURN control, rather than counter magic on the draw Syncopate is gold.
PS: You only truly know a creature is a pirate after they survive your cannonade