Quick Answer
Guildrun Shielding Flask is an event item whose official Demo 0.5.5 update increased its Mana Regen bonus from 4 to 6. The item is most useful when a hero needs more consistent casts and also benefits from a defensive or Shield-oriented plan. The complete current tooltip and any additional effect are To be confirmed unless verified in the live game.
Choose Shielding Flask when Mana Regen addresses the reason the team is losing and the holder can survive long enough to cast. Do not assume the name alone proves a Shield trigger or a universal defensive effect.
The Confirmed Update
The official patch changed Shielding Flask's Mana Regen bonus from 4 to 6. That is the page's current exact value. The patch groups it with other event items, but it does not publish a complete comparison with Toxic Contract or every other Mana Regen source.
This is why version scope matters. A 0.5.4 screenshot may show 4, while the current Demo 0.5.6 page should show the 0.5.5 update. Future patches can change it again, so link to Guildrun patch notes whenever the item is used in a broader build article.
Mana Regen and Survivability
More Mana Regen only helps if the hero can reach the next cast and convert it into a meaningful effect. A fragile caster may need Max HP, Defense, or Shields before additional Mana. The exact interaction between Shielding Flask and every hero is To be confirmed.
Pollen is a natural related page because Sanctuary of Bloom's Poison scaling now benefits more efficiently from Mana Regen in Demo 0.5.6. Skorn is another useful comparison because his Shield and stun-casting changes make a defensive casting window relevant. Neither pairing is an official best-in-slot claim.
Shielding Flask Versus Toxic Contract
Both items are relevant to Mana Regen discussions, but they should not be merged into one page. Toxic Contract is a Rare Item whose base Mana Regen rose from 4 to 6, while Shielding Flask is grouped in the event-item changes. Their full effect differences and trade-offs are To be confirmed.
Read the Toxic Contract guide and Guildrun relics guide for the comparison framework. Choose by the current holder and event choice, not by identical-looking numbers alone.
Event Choice and Timing
The official notes do not publish the complete event choices, costs, or appearance order for Shielding Flask. Mark those fields To be confirmed. When the item appears, ask whether the next encounter rewards a faster cast, a larger Shield window, or immediate damage more strongly.
In a safe fight, preserve flexibility. In a dangerous fight, spend the choice that keeps the engine alive. The correct answer changes with the run because Guildrun offers different heroes, relics, and items between runs.
Current Verdict
Guildrun Shielding Flask currently grants a confirmed Mana Regen bonus of 6, up from 4 in Demo 0.5.5. Use it when faster casts solve the team's actual failure point and the holder can survive, while keeping its complete tooltip, event table, and universal holder rankings marked To be confirmed.