Sienna Resources Inc. — Proxy Solicitation & Information Statement 2025

Nov 5, 2025

SIENNA RESOURCES INC.

Computershare

320 Bay Street, 14th Floor

Toronto, ON M5H 4A6

www.computershare.com

Security Class

Holder Account Number

Form of Proxy - Annual General and Special Meeting to be held on Wednesday, December 17, 2025

This Form of Proxy is solicited by and on behalf of Management.

Notes to proxy

1. Every holder has the right to appoint some other person or company of their choice, who need not be a holder, to attend and act on their behalf at the meeting or any adjournment or postponement thereof. If you wish to appoint a person or company other than the Management Nominees whose names are printed herein, please insert the name of your chosen proxyholder in the space provided (see reverse).
2. If the securities are registered in the name of more than one owner (for example, joint ownership, trustees, executors, etc.), then all those registered should sign this proxy. If you are voting on behalf of a corporation or another individual you may be required to provide documentation evidencing your power to sign this proxy with signing capacity stated. If you are voting on behalf of a corporation you are required to provide your name and designation of office, e.g., ABC Inc. per John Smith, President.
3. This proxy should be signed in the exact manner as the name(s) appear(s) on the proxy.
4. If a date is not inserted in the space provided on the reverse of this proxy, it will be deemed to bear the date on which it was mailed to the holder by Management.
5. The securities represented by this proxy will be voted as directed by the holder, however, if such a direction is not made in respect of any matter, and the proxy appoints the Management Nominees listed on the reverse, this proxy will be voted as recommended by Management.
6. The securities represented by this proxy will be voted in favour, or withheld from voting, or voted against each of the matters described herein, as applicable, in accordance with the instructions of the holder, on any ballot that may be called for. If you have specified a choice with respect to any matter to be acted on, the securities will be voted accordingly.
7. This proxy confers discretionary authority in respect of amendments or variations to matters identified in the Notice of Meeting and Management Information Circular or other matters that may properly come before the meeting or any adjournment or postponement thereof, unless prohibited by law.
8. This proxy should be read in conjunction with the accompanying documentation provided by Management.

Proxies submitted must be received by 10:00 am (Pacific Time), on Monday, December 15, 2025.

VOTE USING THE TELEPHONE OR INTERNET 24 HOURS A DAY 7 DAYS A WEEK!

To Vote Using the Telephone

• Call the number listed BELOW from a touch tone telephone.

1-866-732-VOTE (8683) Toll Free

To Vote Using the Internet

• Go to the following web site: www.investorvote.com
• Smartphone? Scan the QR code to vote now.

To Receive Documents Electronically

• You can enroll to receive future securityholder communications electronically by visiting www.investorcentre.com.

If you vote by telephone or the Internet, DO NOT mail back this proxy.

Voting by mail may be the only method for securities held in the name of a corporation or securities being voted on behalf of another individual.

Voting by mail or by Internet are the only methods by which a holder may appoint a person as proxyholder other than the Management Nominees named on the reverse of this proxy. Instead of mailing this proxy, you may choose one of the two voting methods outlined above to vote this proxy.

To vote by telephone or the Internet, you will need to provide your CONTROL NUMBER listed below.

CONTROL NUMBER

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Appointment of Proxyholder

I/We being holder(s) of securities of Sienna Resources Inc. ("Sienna") hereby appoint: Jason Gigliotti, a Director of the Company, or failing this person, Dennis Aalderink, a Director of the Company (the "Management Nominees")

OR

Print the name of the person you are appointing if this person is someone other than the Management Nominees listed herein.

as my/our proxyholder with full power of substitution and to attend, act and to vote for and on behalf of the holder in accordance with the following direction (or if no directions have been given, as the proxyholder sees fit) and on all other matters that may properly come before the Annual General and Special Meeting of shareholders of Sienna to be held at Cozen O'Connor LLP, office at 2501 - 550 Burrard Street, Vancouver, BC V6C 2B5 on Wednesday, December 17, 2025 at 10:00 am (Pacific Time), and at any adjournment or postponement thereof.

VOTING RECOMMENDATIONS ARE INDICATED BY HIGHLIGHTED TEXT OVER THE BOXES.

	For	Against
1. Number of Directors	☐	☐
To set the number of Directors at four (4).
2. Election of Directors	For	Withhold
---	---	---
01. Jason Gigliotti	☐	☐
04. Negar Adam	☐	☐

1. Appointment of Auditors

To appoint Davidson & Company LLP, Chartered Professional Accountants, as auditors of Sienna until the next annual meeting of shareholders and authorize the directors to fix their remuneration.

For	Against

1. Approval of Omnibus Equity Incentive Plan

To consider, and if thought fit, to pass an ordinary resolution, to approve and adopt the Company's Omnibus Equity Incentive Plan (the "2025 Plan") to replace the current omnibus incentive plan (the "Predecessor Plan").

For	Against

1. Transaction of Other Business

To transact such other business as may properly come before the Meeting or any adjournment thereof.

Signature of Proxyholder	Signature(s)	Date
I/We authorize you to act in accordance with my/our instructions set out above. I/We hereby revoke any proxy previously given with respect to the Meeting. If no voting instructions are indicated above, and the proxy appoints the Management Nominees, this Proxy will be voted as recommended by Management. If you are voting on behalf of a corporation you are required to provide your name and designation of office, e.g., ABC Inc. per John Smith, President.		DD / MM / YY
	Signing Capacity

HAOQ

380051

AR0

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